Blockchain Tutorial

What exactly is Blockchain?

Blockchain is defined as a chain of information-containing blocks. The technique is intended for timestamping digital documents so that they cannot be backdated or tempered. The goal of blockchain is to solve the problem of duplicate records without the need for a central server.

The blockchain is utilized for securely transferring items such as money, property, contracts, and so on without the need for a third-party intermediary such as a bank or government. It is extremely difficult to change data once it has been recorded within a blockchain.

The blockchain is a computer software protocol (like SMTP is for email). Blockchains, on the other hand, could not function without the Internet. It is also known as meta-technology since it has an impact on other technologies. It is made up of several components, including a database, a software application, and some connected computers.

The term is sometimes utilized for referring to the Bitcoin Blockchain or the Ethereum Blockchain, and other times it is used for referring to other virtual currencies or digital tokens. However, the majority of them are referring to distributed ledgers.

In this Blockchain tutorial for beginners, let us learn the fundamentals of Blockchain.

What Blockchain is not about:

  1. Blockchain is not the same as Bitcoin, but it is the technology that powers Bitcoin.
  2. The digital token is bitcoin, and the blockchain is the ledger that keeps track of who owns the digital tokens.
  3. Bitcoin cannot exist without blockchain, but a blockchain can exist without Bitcoin.

Architecture of Blockchain

In this Blockchain Technology tutorial, let us look at the Blockchain architecture and its various components:

What exactly is a block?

A blockchain is a chain of information-containing blocks. The data stored within a block is determined by the type of blockchain.

A Bitcoin Block, for example, contains information about the Sender, Receiver, and the number of bitcoins to be transferred.

The Genesis block is the first block in the chain. Each new block in the chain is linked to the one before it.

SHA256 – Hash

A hash is also part of a block. A can be thought of as a unique fingerprint for each block. It identifies a block and all of its contents and is always unique, similar to a fingerprint.

As a result, once a block is created, any change within the block will cause the Hash to change.

As a result, the Hash is extremely useful when detecting changes to intersections. If a block’s fingerprint changes, it is no longer the same block.

Each Block has

  1. Data
  2. Hash
  3. Hash of the previous block

Consider the following example, in which we have a three-block chain. There is no predecessor to the first block. As a result, it lacks the hash of the previous block. A hash of block 1 is contained in block 2. Block 3 contains the Hash of block 2.

As a result, all blocks contain hashes of previous blocks. This is the method that ensures the security of a blockchain. Let us see how it works –

Assume an attacker can alter the data in Block 2. As a result, the Hash of the Block changes. However, Block 3 still contains Block 2’s old Hash. As a result, Block 3 and all subsequent blocks are invalid because they lack the correct Hash of the previous block.

As a result, changing a single block can quickly render all subsequent blocks invalid.

Proof of Work Concept 

Hashes are an excellent mechanism for preventing tampering, but modern computers are fast enough for calculating hundreds of thousands of hashes per second. An attacker can tamper with a block in a matter of minutes and then recalculate all the hashes of other blocks to make the blockchain valid again.

Blockchains utilize the Proof-of-Work concept for avoiding this problem. It’s a mechanism that slows down the formation of new blocks.

A proof-of-work is a computational problem that requires a certain amount of effort for solving. However, the time required to verify the results of the computational problem is very less in comparison to the effort required for solving the computational problem itself.

In the case of Bitcoin, calculating the required proof-of-work to add a new block to the chain takes nearly 10 minutes. In our example, if a hacker wanted to change data in Block 2, he would first need to perform proof of work (which would take 10 minutes) before making changes in Block 3 and all subsequent blocks.

This mechanism makes it difficult to tamper with the blocks, even if you tamper with a single block, you will need to recalculate the proof-of-work for all subsequent blocks. As a result, hashing and proof-of-work mechanisms ensure the security of a blockchain.

Distributed P2P Network 

However, blockchains utilize another method for securing themselves, and that is by being distributed. Instead of relying on a central entity for managing the chain, Blockchains rely on a distributed peer-to-peer network that anyone can join.

When someone joins this network, they will receive a complete copy of the blockchain. Each computer is referred to as a node.

Let’s take a look at what happens when any user adds a new block. This new block is distributed to all network users. Each node must verify the block for ensuring that it has not been tampered with. Each node adds this block to their blockchain after it has been thoroughly checked.

This network’s nodes all generate an agreement. They have reached an agreement on which blocks are valid and which are not. Nodes in the network will reject tampered with blocks.

So, how does one successfully tamper with a blockchain?

  1. One must tamper with every block on the chain.
  2. Recreate the proof-of-work for each block.
  3. Take control of more than 50% of the peer-to-peer network.

After you’ve completed all of these steps, your tampered block will be accepted by everyone else. This is a near-impossible task. As a result, Blockchains are extremely secure. Following that, in this Blockchain development tutorial for beginners, we will learn how a Blockchain transaction works.

Working of Blockchain Technology 

Step 1: A transaction is requested by someone. The transaction may include cryptocurrency, contracts, records, or other data.

Step 2: The requested transaction is broadcasted to a peer-to-peer network using nodes.

Step 3: Using well-known algorithms, the network of nodes validates the transaction and the user’s status.

Step 4: When the transaction is finished, the new block is added to the existing blockchain. In a way that is permanent and irreversible.

Necessity for Blockchain 

Here are some of the reasons why Blockchain technology has grown in popularity.

Resilience: Blockchain architecture is frequently replicated. In the event of a massive attack on the system, most nodes continue to operate the chain.

Time savings: In the financial industry, blockchain can play an important role by allowing for faster trade settlement because it eliminates the need for a lengthy process of verification, settlement, and clearance because all stack holders have access to a single version of agreed-upon data of the shared ledger.

Reliability: Blockchain validates and certifies the identities of the parties involved. This eliminates duplicate records, lowers rates, and speeds up transactions.

Unchangeable transactions: Because Blockchain registers transactions in chronological order, it ensures the unalterability of all operations, which means that once a new block is added to the chain of ledgers, it cannot be removed or modified.

Fraud prevention: The concepts of shared information and consensus help to reduce the possibility of losses due to fraud or embezzlement. Blockchain, as a monitoring mechanism, helps to reduce costs in logistics-related industries.

Security: Attacking a traditional database is equivalent to taking down a specific target. Using Distributed Ledger Technology, each party holds a copy of the original chain, ensuring that the system remains operational even if a large number of other nodes fail.

Transparency: All changes to public blockchains are visible to the public. This increases transparency, and all transactions are unchangeable.

Collaboration: It enables parties to transact directly with one another without the need for a third party to act as a middleman.

Decentralized: Some rules govern how each node exchanges blockchain information. This method validates all transactions and adds all valid transactions one by one.

Versions of Blockchain 

Blockchain Version 1.0: Currency

The use of DLT (distributed ledger technology) resulted in its first and most obvious application: cryptocurrencies. This enables blockchain-based financial transactions. It is used in payments and currency. Bitcoin is the most visible example in this category.

 Blockchain 2.0: Smart Contracts 

Smart Contracts, which are small computer programs that “live” in the blockchain, are the new key concepts. They are free computer programs that run automatically and check previously defined conditions such as facilitation, verification, or enforcement. It is used in place of traditional contracts.

 Blockchain 3.0: DApps

DApps are an abbreviation for decentralized applications. Its backend code is hosted on a decentralized peer-to-peer network. A DApp, like a traditional App, can have frontend Blockchain example code and user interfaces written in any language that can make a call to its backend.

Variants of Blockchain 


Ledgers in this type of blockchain are visible to everyone on the internet. It enables anyone to verify and add a transaction block to the blockchain. People are encouraged to join public networks, which are also free to use. A public blockchain network is accessible to anyone.


The private blockchain exists only within one organization. It permits only specific members of the organization to verify and add transaction blocks. However, it is generally permissible for anyone on the internet to view it.


Only a select group of organizations can verify and add transactions in this Blockchain variant. The ledger can be made public or restricted to specific groups in this case. A consortium blockchain is used by multiple organizations. Only pre-authorized nodes can control it.

Use cases of Blockchain 

Blockchain technology is widely used in a variety of industries, as shown below.

Market Sector 

  1. Billing, monitoring, and Transfer of Data
  2. Management of quotas in the Supply Chain Network

Government Sector 

  1. Services for personalized transnational governance
  2. Voting, P2P bond propositions
  3. Document/contract digitization and proof of ownership for transfers
  1. Registry & Identify
  2. Tele-attorney service
  3. Registration and exchange of IP addresses
  4. Tax receipts Notary service and document registry


  1. Agricultural & drone sensor networks
  2. Smart home networks
  3. Integrated smartcity.
  4. Smart home sensors
  5. Self-driving car
  6. Personalized robots, robotic component
  7. Personalized drones
  8. Digital Assistants

Health Sector 

  1. Data management
  2. Universal EMR Health databanks
  3. QS Data Commons
  4. Big health data stream analytes
  5. Digital health wallet Smart property
  6. Health Token
  7. Personal development contracts

Science and Art Sector 

  1. Supercomputing
  2. Crowd analysis
  3. P2P resources
  4. Digital mind fit services

Finance and Accounting Sector 

  1. Digital Currency Payment
  2. Payments & Remittance
  3. Decartelized Capital markets using a network of the computer on the Blockchain
  4. Inter-divisional accounting
  5. Clearing & Trading & Derivatives
  6. Bookkeeping

Real-life use cases of Blockchain 

  1. Dubai: The Smart City

The Blockchain strategy was introduced by the Smart Dubai office in 2016. Entrepreneurs and developers will be able to connect with investors and leading companies using this technology. The goal is to implement a blockchain-based system that promotes the development of various industries to make Dubai “the happiest city in the world.”

  1. Incent Customer retention

Incent is a Blockchain-based CRaaS (Consumer retention as a service). It is a loyalty program that generates tokens for businesses that are part of its related network. Blockchain is exchanged instantly in this system, and it can be stored in digital portfolios on user phones or accessed via the browser.

  1. Blockchain for Humanitarian Aid

The United Nations World Food Program launched a humanitarian aid project in January 2017. The project was created in rural areas of Pakistan’s Sindh province. Beneficiaries received money, food, and all types of transactions are registered on a blockchain to ensure the security and transparency of this process.

Most Popular Application of Blockchain: Bitcoin Cryptocurrency 


A cryptocurrency, like traditional currencies such as USD, is a medium of exchange that is designed to exchange digital information through a process made possible by certain cryptographic principles. A cryptocurrency is a type of digital currency that falls under the subset of alternative currencies and virtual currencies.

Cryptocurrency is a digital cryptographic bearer instrument. The holder of the currency owns the cryptocurrency in this case. There is no other record of the owner’s identity. Wei Dai released “B-Money,” an anonymous, distributed electronic cash system, in 1998.


Bitcoin was created in 2009 by an unknown individual known as Satoshi Nakamoto. Bitcoin is a peer-to-peer technology that is not controlled by a central authority or banks. At the moment, issuing Bitcoins and managing transactions are done collectively in the network. It is currently the world’s most dominant cryptocurrency.

Because it is open source and intended for the general public, no one has control over Bitcoin. There are only 21 million Bitcoins in circulation. Bitcoin currently has a market capitalization of $12 billion.

Anyone can use bitcoin without having to pay any transaction fees. When dealing with Bitcoin, the sender and receiver transact directly without the use of a third party.

Blockchain and Bitcoin 

The blockchain is the technology that powers Bitcoin. The digital token is bitcoin, and the blockchain is the ledger that keeps track of who owns the digital tokens. Bitcoin cannot exist without blockchain, but blockchain can exist without Bitcoin.

Other prominent cryptocurrencies are:

  1. Ethereum
  2. Bitcoin Cash
  3. Ripple
  4. Litecoin

Blockchain vs. Shared Database

Parameter: Operations

Blockchain: Insert

Shared Database: Create/ Read/ Update and Delete

Parameter: Replication 

Blockchain: Full replication on every peer

Shared Database: Master-slave


Parameter: Consensus 

Blockchain: The majority of peers agree on the outcome of transactions.

Shared Database: Commit and Paxos are two phases of distributed transactions.

Parameter: Validation 

Blockchain: Global rules govern the entire blockchain system.

Shared Database: Only provides local integrity constraints.

Parameter: Disintermediation

Blockchain: It is allowed with blockchain.

Shared Database: Not allowed.

Parameter: Confidentiality

Blockchain: Fully confidential

Shared Database: Not confidential

Parameter: Robustness

Blockchain: Fully robust technology.

Shared Database: Not entirely robust.

Myths regarding Blockchain 

Myth: It solves every problem

Reality: No, it is just a database

Myth: Trustless Technology

Reality: It has the ability to both shift and spread trust.

Myth: Secure

Reality: It prioritizes integrity over confidentiality.

Myth: Smart contracts are always legal

Reality: It only carries out parts of some legal contracts.

Myth: Immutable

Reality: It only offers probabilistic immutability

Myth: Need to waste electricity

Reality: Emerging blockchains are efficient

Myth: It is inherently unsalable

Reality: Emerging blockchains are scalable

Blockchain Technology Applications 

Let’s take a look at some common applications of Blockchain:

  1. Its purpose is to create a secure and transparent digital ledger of all transactions.
  2. It enables you to create a tamper-proof record of academic achievement that all students and teachers can access.
  3. It is employed in the development of a more efficient system for trading securities.
  4. Smart contracts are used by lenders to execute collateralized loans on the blockchain.
  5. The use of blockchain technology to record real estate transactions can provide a more secure and accessible method of verifying and transferring ownership.
  6. Use on a public ledger to store data such as a Social Security number, date of birth, and other identifying information.
  7. Blockchain technology is also used in the logistics industry, where it aids in the tracking of items as they travel through a logistics or supply chain network.

Blockchain technology limitations 

In these beginners Blockchain tutorial, we will learn about the following Blockchain technology limitations:

Higher costs: In a business that operates on the supply and demand principle, nodes seek higher rewards for completing transactions.

Slower transactions: Because nodes prioritize transactions with higher rewards, transaction backlogs accumulate.

Smaller ledger: It is not possible to create a full copy of the Blockchain, potentially affecting immutability, consensus, and so on.

Transaction costs, network speed: After being marketed as “nearly free” for the first few years, Bitcoin’s transaction costs have risen significantly.

Error risk: As long as the human factor is present, there is always a risk of error. If a blockchain is used as a database, all incoming data must be of high quality. Human intervention, on the other hand, can quickly resolve the error.

Wasteful: Every node that runs the blockchain is responsible for maintaining blockchain consensus. This results in very little downtime and makes data stored on the blockchain permanently unchangeable. However, all of this is inefficient because each node must repeat a task to reach a consensus.

Blockchain Council 

Blockchain Council offers blockchain certification, which is specifically designed for people who want to pursue a career in the blockchain domain. This certification necessitates a thorough understanding of the fundamental concept of blockchain. It focuses on applications such as Corda, Smart Contracts, Hyperledger, and Quorum.

Working in industries such as digital marketing, healthcare, and supply chain can benefit from Blockchain Council certification.

This organization’s training and certification are beneficial to a wide range of enterprises, businesses, and developers. As a result, Blockchain technology is being used on the centralized and traditional working system business.

The Blockchain Council has provided the following certificates:

  1. A Certified Blockchain Expert
  2. Certified Corda Expert
  3. Certified Corda Architect
  4. Certified Blockchain Developer
  5. Certified Blockchain Security Professional
  6. Certified Smart Contract Developer
  7. Certified Bitcoin Expert
  8. Certified Ethereum Expert


  1. A blockchain is a series of blocks that contain data.
  2. The blockchain is not Bitcoin itself, but it is the technology that powers Bitcoin.
  3. Every block contains a hash.
  4. Each block has a hash of the previous block
  5. Before a new block can be added to the blockchain, Proof of Work is required.
  6. The blockchain database is distributed among many peers and is not centralized.
  7. Blockchain technology is resilient, decentralized, time-efficient, and provides unalterable transitions.
  8. Blockchain is divided into three versions: Blockchain 1.0: Currency, Blockchain 2.0: Smart Contracts, and Blockchain 3.0: DApps.
  9. There are three different blockchain variants available. 1) Public, 2) Private, and 3) Consortium
  10. The disadvantages of using this technology include higher costs, slower transactions, a small ledger, and the risk of error.
  11. Real-life use cases of Blockchain include Dubai-The Smart City, Incent Customer Retention, and Blockchain for Humanitarian Aid.
  12. Bitcoin makes use of blockchain technology, which is ungoverned by any central authority or banks.

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