User understanding of the content of a website often depends on user understanding of how the website works. This is part of the user experience design. User experience is related to layout, clear instructions, and labeling on a website. How well a user understands how they can interact on a site may also depend on the interactive design of the site. If a user perceives the usefulness of the website

This drives the trend for a more universal user experience and ease of access to accommodate as many users as possible regardless of user skill. Much of the user experience design and interactive design are considered in the user interface design.

Goalkeepers are the only players allowed to play the ball with their hands or arms, provided they do so within the penalty area in front of their own goal. Though there are a variety of positions in which the outfield (non-goalkeeper) players are strategically placed by a coach, these positions are not defined or required by the Laws.

number of players may be replaced by substitutes during the course of the game. The maximum number of substitutions permitted in most competitive international and domestic league games is five in 90 minutes, with each team being allowed one more if the game should go into extra-time; the permitted number may vary in other competitions or in friendly matches. Common reasons for a substitution include injury, tiredness, ineffectiveness, a tactical switch, or timewasting at the end of a finely poised game. In standard adult matches, a player who has been substituted may not take further part in a match. IFAB recommends “that a match should not continue if there are fewer than seven players in either team”. Any decision regarding points awarded for abandoned games is left to the individual football associations.