What is the body and back of a SLR camera?

The fuselage is a single machine without lens, which can realize most functions and operations of SLR cameras, but it can't image without lens.

Back, the 35mm SLR has no back, and the position (sensor) of the fuselage film is fixed. Generally, the back is only available for machines with medium format and large format, which is convenient for changing different films quickly according to different needs. Now, after digitalization, this tradition has survived, and there is also a digital back.