Blockchain Technology is a chain of blocks containing information that is a secure and decentralized digital ledger of transactions verified by miners and cannot be falsified. Furthermore, it is a distributed database that everyone can get a copy of, and every person with a copy can add new records to this database but cannot change any record once its there, which makes the blockchain great to record data transparently as everyone gets to see what’s in it.

A record of the transaction is added to every participant’s ledger whenever a new transaction occurs on the blockchain. Thus, a decentralized database by multiple participants is known as Distributed Ledger Technology (DLT).

The Properties of Distributed Ledger Technology (DLT)

Immutable:        Validated records are irreversible.

Time stamper:   Transaction timestamp is recorded on a block.

Distributed:        Participants have a copy of the ledger for complete transparency.

Secure:                Records are individually encrypted.

Unanimous:        Network participants agree to validate each of the records.

Anonymous: The identity of participants is either anonymous or pseudonymous

Programmable:  Blockchain is programmable (i.e., Smart contracts )

Distributed Ledger Technology

The primary purpose of blockchain is to timestamp digital documents so that it’s not possible to backdate them or temper them ( almost like a notary). Each block contains some data (the hash of the block and the previous block’s hash). The data that is stored inside a block depends on the type of blockchain. For example, the Bitcoin blockchain stores the details about a transaction (such as the sender, receiver and amount of coins).

 A block also has a hash that defines the block and its contents, and it’s always unique (just as a fingerprint). Once a block is created, its hash is calculated, and changing something inside the block will cause the hash to change. So, if the fingerprint of a block changes, it no longer is the same block. The third element inside each block is the hash of the previous block. This effectively creates a chain of blocks which makes a blockchain so secure.

 Computers these days are very fast and can calculate hundreds of thousands of hashes per second. So one could effectively tamper with a block and recalculate all the hashes of other blocks to make the blockchain valid again. So to mitigate this, blockchains have a “proof–of–work” phenomenon, making it very hard to tamper with the blocks (if you tamper with one block, you will need to recalculate the proof-of-work for all the following blocks).


Blockchains use the peer-to-peer network, and anyone is allowed to join. Blockchains are also constantly evolving. One of the more recent development is the creation of smart contracts. These contracts are simple programs stored on the blockchain and can automatically exchange coins based on certain conditions. This technology can be used to create a digital notary, store medical records, or even collect taxes.

Applications of Blockchain Technology :

Now that you understand blockchain, you are still confused about how this technology can be used in the real world.

Let’s take a look at a few examples

  • Cryptocurrencies:

 Bitcoin launched in 2008 allowed people to directly transact with one another without having to trust third parties like banks. Since then, over 1600 different cryptocurrencies have been created

Applications of Blockchain Technology

  • In cars:

Ever heard of odometer fraud? By tampering with the odometer, someone can make a car appear new (where the vehicle is worn out), resulting in customers paying more than what the car is worth. Replacing regular odometers with smart ones connected to the internet and frequently writing the car’s mileage to a blockchain can create a secure and digital certificate for each vehicle. And because of using blockchain, no one can tamper with the data, and everyone can look up a vehicle’s history. This already is developed by Bosch’s loT, and they are currently testing it on a fleet of 100 cars in Switzerland and Germany.

  • Keeping record: Besides odometers, you can also keep track of things like intellectual property or patients or even function as a notary. For example, the online website “” allows you to add documents to the Bitcoin or Ethereum blockchain. Once added, you can always prove that you created a record at a certain point in time, much like a notary.
  • Digital voting : 

Another exciting application is digital voting. Right now, voting happens either on paper or on special computers that are running proprietary software. Voting on paper costs a lot of money, and electronic voting has security issues. So we can use blockchains to cast and store votes. Such a system would be very transparent as everyone could verify the voting court for themselves, making tampering with it very difficult.

Digital voting

  • Tracing the origin of stuff :

Food products can be tracked with blockchain technology from the moment they are harvested to the point they end up in customers’ hands. A ratio of people die because of food-borne diseases, and that’s because it takes too long to isolate the food that is causing harm. Blockchains could help us create a digital certificate for each piece of food, proving where it came from and where it has been. So if a contamination is detected, we can trace it back to its root and instantly notify other people who bought the same batch of lousy food.

A system like this could be applied to other industries as well. For example, we could use it to track regular products and battle counterfeit goods by allowing anyone to verify whether or not the product comes from the manufacturer you think it does.

Another idea would be to track packages and shipments by using a blockchain. That is something that IBM and container shipping giant Maersk are working on a decentralized ledger to help with making the global trade of goods more efficient.

  • Smart contracts:

Blockchains can be even more powerful when we add smart contracts to them. These contracts are tiny computer programs that live on the blockchain and can perform actions when certain conditions are met. For example, insurance companies can use smart contracts to validate claims and calculate a payout. Or they can allow us to only pay for car insurance when we are driving.

With smart contracts, we can secure our data on a blockchain. They could, for instance, allow us to store our medical records on a blockchain and only allow doctors to access them when we approve them with a digital signature. Likewise, you could store your identity there and choose what data you want to reveal in the same fashion.

Smart contracts

A future streaming service could set up two smart contracts: one where users send their monthly subscriptions and one that keeps track of what they have listened to.

Studying blockchain technology:

Below is the list of the free online courses to learn Blockchain technologies (and how to work with them).

These courses will teach you the fundamentals about BlockChain and how it works, and you will get familiarized by creating a smart contract and your private network.

1- Introduction to Cryptocurrencies and Blockchain.

2- Blockchain Technology by edX.

3- Blockchain principles and practices.

4- Ethereum Development Course – Blockchain at Berkeley.

5- Blockchain Basics by Coursera.

6- Blockchain fundamentals.

7- Enterprise Blockchain Fundamentals.

8- Blockchain Theory 101. (Udemy)

9- Blockchain and deep learning (by Udemy).

10- Introduction to Hyperledger Blockchain Technologies

11- Blockchain essentials.

Studying blockchain technology

How to become a blockchain developer

  • Becoming a blockchain developer is within your reach, for which you firstly should Get familiar with the basics of Blockchain including Miners, cryptocurrency, node, private key, public key, proof of work, proof of stake, decentralization, dApp.
  • It would help if you learned everything about bitcoin, ethereum etc.
  • It would be best if you keep yourself up-to-date about the latest news from trustworthy sources (like CoinDesk, Cointelegraph, CCN TodayOnChain, BTC Wires)
  • You should know about Blockchain Development.
  • You should learn various Programming Languages.
  • You should have Blockchain Developer Courses.
  • You should join the community of blockchain developers and take feedback from them as well.
  • You should develop your blockchain application

blockchain developer