Basement flooded

What causes a basement to flood?

Hey girls is it bad to move heqvy stuff I'm nine months pregnant and have been moving things out of the way. The basement is wet I don't know where the water is coming from not the shower not the washing machine not the bathroom pipes at least it doesn't smell so what's the problem??

It rained a huge storm two days ago besides that mostly cold temperatures the 40s and windy.