What is a block chain?

This is my understanding
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"Think of the hash that starts with 0000 as a winning lottery ticket.

I have a base ticket (the block data), but that alone won’t win. So, I keep adding different numbers (nonces) to it — like writing random guesses on my ticket — and checking if it turns into a winning one (i.e., gives a hash that starts with 0000).

I keep trying again and again until finally... boom! I get a winning ticket. That’s my valid block."

So yes:

Your base data (block info) = ticket

Nonce = extra number you add to try and win

Hash with 0000 = winning ticket

Trying again and again = mining / Proof of Work