“When you read source code, often you need to look for
definitions of functions, classes, or other objects. Editors such
as Emacs and Vim help you browse the code by supporting the concept
of tags. You can think of tags as labels that can be jumped to.“Each such label is actually a filename and a position in a file
(stated via a line number or a regular expression), stored in a
tags table file. Just what names from the described files are
recorded in the tags table depends on the programming language and
the tool you use to generate the tags table…”