A thumbscrew is a fastener that works like a screw, but is screwless, meaning that it doesn’t require any tools. It is tightened and loosened by the user’s thumb and index finger. The picture shows an example of a thumbscrew used on computer cases. Because these screws are often found on computer cases, they’re also often called case screws.
Hardware terms, Screw
There are also Phillips and slotted thumbscrews.
