From IFWiki

(1) An integer of points out of a maximum score which represents how far the player has progressed through the game. For example, "189 out of 200 points" would indicate the player is quite close to completion. It is often possible to complete a game without the full number of points, sometimes irritatingly just one short (see last lousy point). Some modern IF games do not have a score system.

(2) The command (usually a meta-command) to see the player's current score. Some systems such as Inform allow a "full score" system which displays a breakdown of each point-gaining action, and even a rank based on their progress (e.g. "You have scored 3 out of 100 points, giving you the rank of Novice" or "You have scored 212 out of 250 points, giving you the rank of Expert.")