A hosted (shared) web-based EWallet used for sending, receiving and storing bitcoins.
This is not to be confused with the data structure in the blockchain which is also named coinbase. This also is not to be confused with a podcast series called Coinbase that was produced by AgoristRadio.com.
The service aims to be the easiest way to get started with Bitcoin. Its service is modeled to provide an experience familar to those who are comfortable using PayPal.