As the terms suggest, custodial products are products that have someone acting as a trusted party that holds something valuable on behalf of others and the other way round for non-custodial. In the context of wallets, non-custodial wallets give users access to their private keys (PK). Literally, they have full control of their funds and their PK never leaves their devices. One widely used non-custodial wallet is Atomic Wallet, It supports multiple coins and they all have distinct private keys which can be easily retrieved