Skimmer system
The final link in the pool recirculation system: skimmer-pump-filter-returns are the water returns.
Typically these are referred to as "eyeballs" as they incorporate a swiveling nozzle that can be locked down to point in the desired direction and are reminiscent of a swiveling human eyeball. The directional adjustment is usually a 360 degree radius circle of 45 degrees away from the pool wall. Most home pools would incorporate at least two such "eyeballs". Skimmers should always have a leaf basket or filter between it and the pump to avoid blockages in the pipes leading to the pump and filter.

Overflow system
An overflow channel is a gutter that surrounds the pool, covered by a removable grille. Surface water flows over the edge of the pool and runs by gravity to the filtration plant, usually via a catchment and
top-up tank.
Overflow channels allow faster turnover of the surface water than is possible with simple weir skimmers, which is why they are commonly found in most pools nowadays. They can also be attractive designs, particularly when transformed into a total "vanishing edge" pool.