A temporary storage space or memory that allows fast access to data.
In more technical sense, a cache is a small amount of faster, more expensive memory used to improve the performance of recently or frequently accessed data. Cached data is stored temporarily in an accessible storage media that's local to the cache client and separate from the main storage. Cache is commonly used by the central processing unit (CPU), applications, web browsers and operating systems.
Cloud storage is an alternative to storing data on a computer’s physical storage. Information stored “on the cloud” is kept on remote servers that can be accessed anywhere via the Internet.
CPU stands for the Central Processing Unit. It is the processing chip that serves as the "brains" of a device that interprets (or processes) the digital instructions provided by applications.