What is a cryptocurrency web wallet?

A cryptocurrency web wallet is a wallet that can be accessed directly through a browser interface without the need to download additional software. Sometimes you can create a wallet and password to access it yourself but many companies manage private keys on behalf of their users, which is very convenient for beginners but less secure. If the user does not own the private keys, this means that he trusts his funds to a third party in full or in common ownership using multi-signature.