You will not be a blockchain noob anymore after reading this
When I was educating myself on Blockchain, this is how I summarized it in one sentence:
Blockchain is a series of events whose sequence is recorded.
If you could know only one thing about Blockchain, this should be it. However, if you are more curious, here's a deeper explanation:
Blockchain = "Block" + "Chain". Blockchain is a chain of blocks.
Blockchain = Block 1 --> Block 2 --> Block 3........Block 'n'
A block itself is a collection of events. Let's understand using your day as an example. If someone were recording your daily actions on an excel spreadsheet, keeping one column for one day's actions, and moving to the next column every day, each column would be a block.
Block: You woke up >> Ate breakfast >> Ate lunch >> ..... >> Slept
At the end of the year, there will be 365 columns (or blocks). These blocks in a fixed sequence (calendar year) will form a blockchain.
[Bonus]: Blockchain is a technology. Cryptocurrencies (Bitcoin, Ethereum), NFTs, and Web3 are applications of this technology.