VPS is most often used to designate a virtual server provider, where by the provide you with virtual servers but not many higher level features.

A Cloud provides you with virtual servers like a VPS provider, but also layers in additional services such as load balancing, block storage, object storage, managed databases, and so forth.

A VPS provider is a great way to get started while a Cloud is a great place to build out a production application and take advantage of the higher level features and abstractions that they provide.