Self is a reference to the object on which the current method operates.
Related concepts: ObjectReferenceMethod
Closest Wikipedia entry: This (computer programming) — this, self, and Me are keywords used in some computer programming languages to refer to the object, class, or other entity of which the currently running code is a part. The entity referred to by these keywords thus depends on the execution context (such as which object is having its method called). Different programming languages use these keywords in slightly different ways.