Bitcoin Improvement Proposals (BIPs) are proposals for improving the Bitcoin network. BIPs 44, 49, 84 and 86 specifically refer to different address formats used in Bitcoin.

BIP44: BIP44 addresses typically start with the number "1" and are known as legacy addresses. It’s the oldest form.

BIP49: These addresses start with the number "3" and are called SegWit addresses. SegWit (Segregated Witness) is a technology upgrade that optimizes transaction sizes and improves scalability. So, if you’re using the BIP49 wallet, transactions are expected to be faster than BIP44.

BIP84: These addresses start with "bc1" and provide further efficiency improvements in terms of transaction fees and block space utilisation. So, if you’re using BIP84 address, the transaction fees are expected to be lower, compared to BIP49 and BIP44. This is the most stable and recommended.

BIP86: It’s the latest address format and starts with “bc1”. It’s very similar to BIP84.

Coinosh Wallet supports all these address formats, allowing users to have separate Bitcoin balances and transactions for each format within a single wallet. But BIP84 is the most recommended.

When restoring a Bitcoin wallet, it's important to know the address format used in the original wallet to ensure compatibility with the wallet app.