1. Alternatively referred to as a return key, the enter key when referring to a keyboard is used to return a cursor to the next line or execute a command or operation. It is common for most standard keyboards to have two enter or return keys, one on the keyboard and another on the numeric keypad.
2. In general, enter or entering refers to when data is being placed into the computer. For example, when searching for something in a search engine such as Google you are entering a query or set of words you want to find more information about.