What is SegWit or legacy Coinbase?

SegWit, short for Segregated Witness, is a technical upgrade in the Bitcoin network that improves transaction scalability and security by separating signature data. Legacy Coinbase refers to the older version of Coinbase platform or its services before certain upgrades or changes, though the term is not widely used; Coinbase itself is a renowned cryptocurrency platform providing secure storage, trading, and education services for various cryptocurrencies like Bitcoin and Ethereum.