A hop and pop — sometimes written hop 'n' pop — is a skydive where the jumper deploys their parachute within a few seconds of leaving the aircraft, typically from a lower altitude than a normal jump.
Why anyone would want one
Licence progression requires demonstrating a clean low-altitude exit and deployment, so most jumpers do them as part of training.
Canopy pilots use them deliberately: if the goal is canopy flight, a hop and pop from 5,000 feet gives more useful time under the wing than a full-altitude jump and costs less.
They are also what happens when an aircraft has a problem and everyone needs to leave promptly — which is why the skill is trained rather than optional.
Not a beginner's shortcut
Less altitude means less time to deal with a deployment problem. Drop zones apply their own minimums and expect the exit and deployment to be clean and consistent before signing anyone off.
These pages explain what things are so the language makes sense. They are not instruction and cannot substitute for it — skydiving is taught in person by rated instructors at a drop zone, and anything involving equipment handling or emergency procedures belongs there rather than on a web page.