Basically, both of the features comes under the umbrella of Google and are used for the storage of data.

Moreover, Google cloud is a disk in the cloud server where you can store the data and is used mostly by the developers as it is very difficult to manage by a non technical person. It can be accessed through VM or DNS

Whereas, Google drive is also used for the storage of data but it’s UI is quite simple to operate and even a lay man can do his work on it. It can be accessed through a browser or even a mobile app.