Answer 1

equals() returns true if two objects are the same. Otherwise false.
hashCode() returns a hashcode for an object.

If both methods are correct implemented two objects which are equal have the same hashCode.

For own classes you have to override both. But only if you need them.

You can read this for more explanation: https://www.baeldung.com/java-equals-hashcode-contracts

And here is a code:
https://code.sololearn.com/cK2H7CdVEq45/?ref=app