How do you define focus? In photography, it helps to view focus as a broader term referring to the plane of focus. Within the plane of focus is the space where the image will look as sharp as possible. Cameras with a focus lens offer you the ability to move the place forward and backward to adjust the focus. Most cameras come with two options in terms of focusing: autofocus and manual focus.
When using the autofocus function, you’re allowing the focus motor to adjust to change focus. When you manually focus a camera, you’re adjusting the lens yourself to bring your subject into focus as you want it to be.
Modern cameras that allow for autofocusing are often helpful when tracking a moving subject, such as the case in sports photography or wildlife photography. While it’s often the more convenient option, autofocus doesn’t allow for as much control as manual focus.