A shop vac is a round canister type vac with a hose and attachments. It's not as easy to use in the house as a house vacuum, which is usually an upright or a canister with different attachments. It can be used to vacuum dust, debris, or even liquids. A shop vac is usually more powerful than a house vac. It's very basic, but it does it's job.
I own a Craftsman that will suck a golf ball through a garden hose........