Technically speaking, a blockchain is a type of database. Well, what is a database? With digital technology, it helps to think in terms of how it relates to or mimics the physical world. For example, a blockchain is a type of database in the digital world.
A database, in a way, is like filing cabinets we use in the office. Therefore, the second analogy is to think of a filing cabinet and how you use it to store information.
You have different drawers in the filing cabinet with different files organized in a certain way. For example, the files can be organized in alphabetical order. When you want a file (data), you think about what drawer it is located in, open the drawer, and take out or retrieve the file.
Think of a blockchain as many filing cabinets all chained or grouped together. Using this analogy, you can equate one drawer of the filing cabinet to one block within the blockchain.
Once in place, these blocks never move. Ownership of the information on the blocks can be transferred over and over to different individuals, but the blocks stay in the same location.
Each time you go anywhere on the internet looking for information, you are accessing a database that holds the information. The specific information you retrieve is equivalent to retrieving a file from the digital cabinet. A blockchain is like a file in a cabinet with information in it. Each “block” can have a bundle or group of files in it.
The information in the files cannot be altered by anyone, “it is tamper-proof.” Being tamper-proof or “unhackable” was the secret sauce that enabled bitcoin and cryptocurrencies to begin. In print, Bitcoin with a capital /B/ denotes the blockchain technology or protocol, and bitcoin with the lowercase /b/ denote the digital currency.