An own goal occurs in goal-scoring games when a player scores a goal that is registered against his or her own team. It is usually accidental, and may be a result of an attempt at defensive play that failed or was spoiled by opponents. It is considered one of the most embarrassing blunders in sports.

The term has become a metaphor for any action that backfires upon a person.

In association football , an own goal occurs when a player causes the ball to go into his or her own team's goal, resulting in a goal being scored for the opposition.

The fact that the defending player touches the ball last does not automatically mean that the goal is recorded as an own goal. Only if the ball would not have gone in the net but for the defending player would an own goal be credited. Thus a shot which is already "on target" would not be an own goal even if deflected by the defender. Then the attacker is awarded the goal, even if the shot would have otherwise been easily saved by the goalkeeper. Some scorers will give credit to the attacker if the defender's mistake caused the own goal, similar to ice hockey. The Laws of the Game do not stipulate any rules or procedures for to which players goals are credited, indeed such records are not a compulsory part of the game.

Ownership of property may be private, collective, or common and the property may be objects, land/real estate or intellectual property. Determining ownership in law involves determining who has certain rights and duties over the property. These rights and duties, sometimes called a 'bundle of rights', can be separated and held by different parties.

The question of ownership reaches back to the ancient philosophers, Plato and Aristotle, who held different opinions on the subject. Plato (428/427BC-348/347BC) thought private property created divisive inequalities, while Aristotle (384BC-322BC) thought private property enabled people to receive the full benefit of their labor. Private property also circumvents what is now referred to as the “tragedy of the commons” problem, where people tend to degrade common property more than they do private property. While Aristotle justified the existence of private ownership, he left open questions of (1) how to allocate property between what is private and common and (2) how to allocate the private property within society.

A goal is a desired result an animal, person or a system envisions, plans and commits to achieve—a personal or organizational desired end-point in some sort of assumed development. Many people endeavor to reach goals within a finite time by setting deadlines.

It is roughly similar to purpose or aim, the anticipated result which guides reaction, or an end, which is an object, either a physical object or an abstract object, that has intrinsic value.

Goal-setting ideally involves establishing specific, measurable, attainable, realistic and time-targeted objectives. Work on the goal-setting theory suggests that it can serve as an effective tool for making progress by ensuring that participants have a clear awareness of what they must do to achieve or help achieve an objective. On a personal level, the process of setting goals allows people to specify and then work towards their own objectives — most commonly financial or career-based goals. Goal-setting comprises a major component of personal development. A goal can be long-term or short-term.