A sump pump is a mechanism to remove ground water from the lowest point in your home, (like a basement or crawlspace), along with the soil below, and forces it out into a draining space to avoid flooding, water damage, and mold growth.
A sump pump will stop working if it has no electricity, tripped breaker or GFCI outlet, sump pump switch failure, clogged impellor/intake screen, blocked discharge pipe, no weep hole, or a burned-out pump motor. A sump pump will last about 10 years, but once it stops working, water damage to your home or belongings within it can follow closely behind.