You are referring to legacy bitcoin addresses. Addresses that start from 1.
For the address that is not compressed, its public key will start from 04, while its private key will start from 5.
For compressed, its public key start from 02 or 03, while its private key starts from K or L.
Compressed legacy address has low fee than legacy address that is not compressed.
But for low fee, do not use legacy addresses, use segwit addresses. Addresses that start from bc1.
Sure, SegWit addresses that begin with "bc1" are typically more effective and have cheaper fees than legacy addresses. However, I've learned that although sending Bitcoin from a legacy address to a SegWit address isn't possible but it is possible to send Bitcoin from a SegWit address to a legacy address, and I haven't figured out why.