A sump pump is a pump

Pump

A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...

 used to remove water that has accumulated in a water collecting sump

Sump

A sump is a low space that collects any often-undesirable liquids such as water or chemicals. A sump can also be an infiltration basin used to manage surface runoff water and recharge underground aquifers....

 basin, commonly found in the basement

Basement

__FORCETOC__A basement is one or more floors of a building that are either completely or partially below the ground floor. Basements are typically used as a utility space for a building where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system...

 of homes. The water may enter via the perimeter drains of a basement waterproofing

Basement waterproofing

Basement Waterproofing refers to techniques used to prevent water from entering the basement of a house or other building. Effective below ground waterproofing will include both drainage and sealers....

 system, funneling into the basin or because of rain or natural ground water, if the basement is below the water table level.

Sump pumps are used where basement flooding happens regularly and to remedy dampness where the water table

Water table

The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...

 is above the foundation

Foundation (architecture)

A foundation is the lowest and supporting layer of a structure. Foundations are generally divided into two categories: shallow foundations and deep foundations.-Shallow foundations:...

 of a home.