What is a Label in Compiler Speak?
A Label identifies a location in source code.
This takes the form of an identifier, often followed by a punctuation character, e.g. colon.
There are various examples:
Function labels, switch statements have various case labels, common lisp has something of the form:
(let ((iteration NIL)) (tagbody start (print 'started) (setf iteration 0) increase (print iteration) (incf iteration 1) (go check) check (if (>= iteration 10) (go end) (go increase)) end (print 'done)))
tagbody creates a scope, where labels are define as forms starting with a symbol.