What does wallet mean on Coinbase?

From the Coinbase mobile app:

A negative balance occurs when you buy cryptocurrency or deposit money into your Coinbase account, but Coinbase has not received successful payment from either your bank or card issuer .

It’s directly related to purchasing crypto or depositing fiat currency using a linked bank account. For security reasons , you will not be able to immediately withdraw fiat deposited using a linked bank account or send crypto purchased with such funds off of Coinbase Pro (we call this “withdrawal availability”).

Coinbase Wallet is a self-custody wallet that gives you complete control of your crypto . This means that the private keys (that represent ownership of the cryptocurrency) for your Wallet are stored directly on your mobile device and not with a centralized exchange like Coinbase.com.