Blockchain is the digital and decentralized ledger that records all transactions. Every time someone buys digital coins on a decentralized exchange, sells coins, transfers coins, or buys a good or service with virtual coins, a ledger records that transaction, often in an encrypted fashion, to protect it from cybercriminals. These transactions are also recorded and processed without a third-party provider, which is usually a bank.
This is the simplest and almost complete explanation about blockchain and for the OP i think this is enough for you to understand what is blockchain all about
Blockchain is the world's most trusted all-in- one crypto company, Blockchain is the technology set to change the way we deal with money. With the development of this decentralized ledger system a host of opportunities have opened up.
Adding to the first mentioned this is another characteristic of blockchain thats why many people are converting their money from banks to crypto and specially no third party interception