a character string that is used to identify a machine
a name that is attached to a particular revision of a file and that you can use to check out the desired revision of a file without having to know the exact revision number
a name that uniquely identifies a specific entity in a program
(1) A unique name used to represent an entity such as a field, file, data structure, or label. IBM. (2) One or more characters with visible glyphs, enclosed between angle brackets.