What is the "self" name always referring to...?

[Todd Gardner]

Pardon my extremely ignorant newbie questions.

Where can I go to find more information about the "self" argument?

Is there something special about the word "self" or did Mr. Guido van
Rossum just decide to us the word arbitrarily?

More precisely it seems that most all classes have "self" as the first
parameter.  This may be directly obvious but is the word "self" always
referring to the class or the function it is used in?

Is it a reserved word?

Thank you in advance,

Todd