Power drills come in a variety of sizes, providing power and versatility in a single, fairly compact tool. A power drill is a handheld tool and comes in both a corded and cordless variety. There are power drills that use quick connect for changing drill bits, and drills that still use a chuck key. The supply of bits is not limited to a screwdriver tip and a drill bit. There are single bits and entire cases full of bits available, to serve every need. The types of power drills vary as well- there is a hammer drill, drill driver, right angle drill, screwdriver drill and close quarter drill. Each of these serves a different purpose and functions in similar fashion. Some of them come individually or in kits with other tools, sharing chargers, making the tools more economical and versatile. A few drills come with their own case, making storage and transport easy.