In games, score refers to an abstract quantity associated with a player or team. Score is usually measured in the abstract unit of points, and events in the game can raise or lower the score of different parties. Most games with score use it as a quantitative indicator of success in the game, and in competitive games, a goal is often made of attaining a better score than one's opponents in order to win.
In video games that features a scoring, points are usually an optional, side component of gaming. Players may achieve points through normal gameplay, but their score will often not have an immediate relevance to the game itself. Instead, playing to beat a "high score" set by the game program, another player or onself becomes an extra challenge, adding replay value.
In modern gaming, the presence of a score is not ubiquitous as in the past. Instead during the era of arcade games, when, because of the technical limitations of the time, games could not be "won" or "completed" but were instead endless cycles of continuous gameplay, points had a much greater relevance. Many modern games no longer even keep track of score, and many that do no longer feature an option to save or record high scores. However, some games (particularly role-playing games) have experience points, skill points, and use money (or treasure) which can all be used to buy/upgrade skills/objects, but these are not really considerable scores, being embellishments to their "growing" characters instead of the numerical evaluation of their gaming performance in a given match.
Sometimes the score of a game can have relevance to gameplay. In fighting games, for example, scoring a very high number of points could result in unlockable players or modes. In some games, reaching certain scores gives extra lifes.
In puzzle games, scores are usually gained by solving the puzzles quickly. Higher scores can be gained by performing combos of puzzle solving. There is often a time bonus which can add extra points. The level number is often a multiplier on the points, so higher scores are possible on harder levels. Level multipliers can also be picked up in some games, to further multiply your points bonus.