A Sump
A sump is quite simply an area underneath the surface you are trying to keep dry. This surface is commonly the floor of a basement. Water collects in the earth around your home during rain or light flooding. This water soaks through the soil around your foundation and can find its way to your basement. A sump gives this water someplace else to go. Without a sump, the water would pool in your basement and damage your possessions.
Sump Holes
A sump hole describes the area that constitutes the sump. A sump doesn't necessarily have to be a hole, but if a hole underneath your basement is acting as a sump, it is called a sump hole. This sump hole is simply an area drilled or dug into the ground beneath your basement. The hole is what the water drains into instead of pooling in puddles around your basement. The sump hole also acts like a small water tank and holds the water runoff until it can be removed later.
Multiple Sump Holes
Multiple sump holes can be used to keep a larger area dry. If water tends to pool in different areas of your basement, you can dig sump holes throughout. This gives the water more opportunities to find its way out of your basement and into the sump. Each sump hole should have a pipe fitted into it that allows the water to drain even further into a main sump. This main sump will hold all the water being drained away from your basement via the other sump holes.
Sump Pump
A sump pump is necessary to maintain a sump hole and keep your basement from flooding. A sump does hold water instead of allowing it into your basement, but eventually the sump itself would fill up. Without being able to hold more water, it becomes useless. A sump pump is installed into the sump hole. This pump pulls the water out of the sump and deposits it elsewhere. It can be pumped either into your home's plumbing system or simply outside.