What is the blockchain?


You may have heard of the new buzzword “Blockchain”. Sounds complicated, doesn’t it? Even more so when all the definitions include words like cryptography, ledger, and hashing.

Welcome! My name is Noah, and in this series of posts my goal is to be your tour guide on the journey of understanding what blockchain is and how it affects you and your day-to-day life. In the first article in this series, we are going to go over the groundwork for understanding blockchain and expose you to the core concepts necessary to understand it.

What is blockchain?

Let’s start with an analogy.

Imagine you have a freight train. The train has 4 cars. Each car’s air brake and electricity are connected to the next with the locomotive being the source. Every car is dependent on the car before it for power and brakes.

Now, imagine that the connection between car 1 and car 2 is severed. Cars 2, 3, and 4 lose their ability to brake because each car was linked to the car before it. Now, imagine that we a fifth car to the train. If we break the connection between cars 1 and 2, cars 2, 3, 4, and 5 will lose their ability to brake, and so will every car added after that.

You can think of blockchain similar to the train in our example. Blockchain is a “chain” of information, stored in “blocks”. Say you want to describe the food in your pantry to your friend. You could list every item in the order you see it:

  • Peanut Butter
  • Bread
  • Peanut Butter
  • Raman
  • Raman
  • Raman
  • Bread

Or you could group the items together:

  • 2 Peanut Butters
  • 3 Ramans
  • 2 Breads

By grouping the items together, you have grouped information about what is in your pantry into organized “blocks” of information.

Now, back to our train example.

The blocks in the blockchain are linked together like the cars in our train example. If someone modifies the information stored in a block in the chain, every block after that would lose its connection to that block just as the cars lost their brakes when the connection between the cars was severed.

This gives blockchain the assurance of immutability, i.e., no one can modify the information in any block on the chain without everyone knowing. The feature makes the blockchain a highly secure way of storing information.

Why would someone want to modify the data on the blockchain? What is so important about it?

Well, similar to your bank statement, the blockchain is often used to store a list of financial transactions between two people. If someone could modify those transactions, that person could lie and take money that isn’t theirs.

To prevent this the creators of blockchain technology designed it to be tamper proof so that no person could lie and steal money. This is why the information is store in a block “chain”, to preserve the integrity of the data and make sure that all information on the chain is true and valid. In our next post, we will cover a second way that the blockchain ensures that data stored on the blockchain is secure and tamper-proof. Have a blessed day!

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