How to Understand depth of field while focusing a camcorder

Depth of Field (DoF) is easy to understand, but it is often extremely poorly explained. It's all about selective focus. For consumers with conveniently small camcorders, you only have two options: get your subject away from the background and then (1) zoom in or (2) get the subject close to the camera. No 35mm lens adapters, no secret techniques, no complex math: That's it!