…or, in the good old US of A, that’s “clamped”. One of the times that the US and UK are two countries divided by a common language.
In the classic workbench with a thick slab top, a workpiece is held securely to the bench by a tool called a holdfast.
The problem for me (and others, I’d wager) is that my workbench has a thin skin of plywood for the top. Not ideal, but I built it before I started woodworking and it was perfectly adequate then. Now, not so much. But a lot of stuff has gotten built on it, and it should last until I can build a better bench (on the list!). But a holdfast requires a thicker top to work. So to keep my work from sliding around, I use a different tool.
I use these Irwin clamps for almost everything short of clamping up a carcase. I’ve been using them all day, almost every day for some time now and they’ve held up admirably. I use the 24″ ones mostly. I’ve got a couple of 36″ ones, but they’re too long to hold work on the bench. Really, I couldn’t do much without these clamps, and they’re pretty inexpensive. Definitely worth it.