Why store salt in a database and how to use it?

Question

Node.js

In the database, I store hashes created using bcrypt(Node.js)
Hashing occurs using a specific value salt.
I meet in code examples that people store in the database, in addition to the hash itself, the salt value. What for?
Well, let's say an attacker got a database with hashes, picked up a salt, and started cracking passwords (do I understand the process correctly?). How will storing the value and changing the salt help me? After all, if I change the salt, the hash will also become different, and my entire hash database will become invalid.

Answer 1

Depending on the format in which your function returns the hash, if it already contains a salt, then storing it separately does not make any sense. If we allow you to use this package to calculate and verify the hash, then the hash received there already contains a salt.