Difference between line scan sensor and line scan camera?
The difference is a matter of context. In your drawing, a line scan sensor is a line scan camera.

At the hardware level, though, a line scan sensor is a (usually) CCD chip with 1 to a few rows of photosites. A line scan camera is a unit which incorporates a line scan sensor, support electronics and lens. 

EDIT - Although in some cases a line scan camera does not actually specify a lens. Industrial and scientific models will often be like SLR bodies, and the camera is sold separately from the lens, which the user can provide to fit her needs. Some are sold with the lens provided.