I was going to call this page Vices, but that was too obviously a set up for a cheap joke. But vices are what we use for holding work at the bench, and it is difficult to imagine how I could manage without one. This is the vice that I used when I started model making seriously. It was cheap, and it swivels so one can set it at different angles. I can't think of any other advantages.
The rear jaw is fixed, and the front jaw slides on a pair of rods. The fit on the rods is poor, so there is nothing to keep the jaws aligned. The jaws are removable, thankfully. In many cheap vices they are not even that. As purchased, the inner faces of the jaws were heavily serrated, which marked any soft material such as brass or nickel silver that was clamped, even with a light pressure. I removed the jaws and reversed them (you can just see the serrations in the photograph, now on the outer face), and filed the jaws until they were flat and parallel. Not that they stayed that way when the vice was opened, of course. Finally, the anvil was useless, being mostly unsupported on the rear of the fixed jaw casting, and lacking that essential rigidity.
Some time ago I replaced that with a watchmaker's vice, altogether a better piece of kit. Here the rear jaw slides on a dovetail, rather like the slides on a machine tool, and as a result, the jaws are always parallel. The jaw faces are smooth, and much less likely to mark or damage the work. The vice itself is clamped on to a sole plate which is screwed to the bench top. For small work where very light forces are involved, it is sometimes convenient to remove the vice, with the work in place, and hold it up to eye level, and work on it that way.
While on that subject, it is worth noting that my bench top is 1 metre (or 39 inches in old money) above the floor, considerably higher than the average table top. I prefer to work standing up, meaning that it is not so far to lean over, and when I do sit down, the vice is close to eye level.
The Swiss firm Bergeon make the Rolls-Royce of watchmakers' tools. My watchmaker's vice, from
Cousins, is a copy which does not have quite the same sleek operation and finish, but only costs half the price.