1:01 A blockchain is an innovative form of database. You may have also encountered the terms distributed ledger technology (or DLT), which are frequently used interchangeably.
The characteristics of a blockchain are unique. There are rules for adding data, and once it has been saved, it is difficult to modify or remove it.
Data is progressively added to blocks, which serve as structures. Each block contains a piece of information that refers back to the one before it, and each block is layered atop the one before it. By analyzing the most recent block, we can determine if a new block has been produced since the last one. Consequently, if we continue along the “chain,” we will ultimately reach the genesis block, which is the very first block.
Assume you possess a spreadsheet with two fields for the purpose of comparison. In the first cell of the first row, you may enter any information you choose.
The information from the first cell is converted into a two-letter designation that will be incorporated into the following entry. In this instance, the next cell in the second row (defKP) must contain the two-letter code KP. This means that if you changed the first data (abcAA), every other cell would contain a distinct set of letters.

As seen in Row 4, 1:02 TH is our newest identifier. Remember when we said that entries could not be removed or deleted? Because it would be easy for anyone to determine that it had been completed, they would disregard your effort.
Suppose you changed the information in the first cell; you would receive a new identifier, which would cause the second block to contain different information, resulting in a new identifier in row 2, etc. TH is the culmination of all the information that came before it.
The structure of a blockchain consists of a sequence of blocks that each contain a group of transactions. Before being added to a block, these transactions are collected, digitally signed, and timestamped. Using cryptographic hash functions, the blocks are then connected to create an immutable ledger that prohibits tampering with or altering previous transactions. Due to its potential to revolutionize industries spanning from finance to healthcare, this technology has attracted widespread interest.