King of the hill, or KOTH is a gamemode which you have to capture and hold hills in order to win the game. Hills can generate points once captured, thus KOTH maps are either won once a team has hit a specific point limit, or has the highest amount of points once the time runs out. There is no limit to how many hills there can be on a map.
Traditionally, this variant has 5 hills, which are all required to be captured to win the game. In these type of games, the 5 hills are strung out in a line, with each team already holding the two hills closest to their sides. It is required to capture the preceding hill before capturing other hills. Capturing a new hill generally decreases the amount of time it takes to get back to the middle, as there is a change of the respawn point. This in turn makes it easier to capture new hills, and defend the furthest hill. Alternatively, there are some maps which don't have any hills already claimed by a team, nor with the same layout. These maps are won when all hills are captured.