A "token" is generally used in computing as something to hand around that means something to someone. Yes, this is about as specific as you can get.
The value "as91823010as8f0tqwe123141" doesn't mean anything to you, the user. But it does mean something to the server at www.example.com. What exactly depends. Typically the value itself has no meaning at all. It's just a random value that refers to something stored on the server. It may be a login session. It may be a temporary search result. It may be anything at all.
A token is the equivalent of "here little boy, take this note to your father, he'll know what it means." You as the user are the carrier of the note, which doesn't mean anything to you, but does mean something to the recipient.