Sumps move water from around a home's foundation outside to prevent basement flooding. Sometimes they move sewage out of a home from areas below the level of the sewer plumbing. Some arrangements include two cords and plugs for operation.
Sumps operate in a pit called a sump pit. Water collects in the pit and when it reaches a specific level, the pump turns on and empties the pit. The pump is turned on by a special switch called a float switch. Some float switches have their own cord and plug.
The float switch 'floats' on the water in the pit. When the water level rises above a set level, the switch turns the pump on to empty the water from the pit. When the water level drops again to another set level, the float switch turns the pump off.
Some float switches have their own cord and don't connect directly to the pump. The switch plugs into the outlet and the pump plugs into the back of the switch plug. The switch turns electricity to the pump on and off through this arrangement.