Here's a picture of one if I can paste this in here
Nice little $12 find...
So it may (usually does) have a handle like a hammer, but it's not made for hammering with. Lay the flatter on the work piece and strike the flatter with a hammer.
I've never used one. You may also be interested in discussion of top tools and bottom tools, which I think may be hand held, or fit in the hardy hole.