Pressure Tank

I'm working on a house that was unheated and consequently many pipes burst, flooding the basement. the holding tank that sits on the floor and recieves water from the well pump has a small electric motor on the side that is connected to a switch. I have no clue what it is for, and whether i need the same set up when i go to buy a new tank.

It sounds like that motor and switch on the side of the tank IS your well pump. A picture would be worth a thousand words