Bolt-on neck

Neck joint with a four-screw plate on a Yamaha Pacifica 112 electric guitar
Less-common three-screw assembly with plate, on a Hagström III guitar
Slim bolt-on neck join with chamfered heel and countersunk ferrules on a superstrat electric guitar allows for more comfortable access to top frets
Stephen's Extended Cutaway (on Washburn N4 electric guitar) is another version of bolt-on neck joint

Bolt-on neck is a method of guitar (or similar stringed instrument) construction that involves joining a guitar neck and body using screws or bolts, as opposed to glue and joinery as with set-in neck joints.