Lighting in animation is like lighting in film, except your light source is simulated and produced by the computer over physical light sources. To understand how to make your lighting work in your animation you first have to understand how light reacts to everything in the real world. Lighting can create atmosphere and add realism to an animation where it would otherwise be flat and dull. Animators will often use many different light sources to create the lighting and shadows of an animation.
Rendering builds output files from animations, taking all the compnents, variables and action sequences and turning it into the final compilation. The render can be sequenced images saved singularly or video file. The rendered project can then be displayed using whatever 2D output devices you have.
Rendering is also done to make rough test animations to ensure that character models, environments and other assets and their effects all work in the way they are expected to.
And lastly; Compositing is the compiling of multiple renderings to create the final scenes in an animation with all their effects in place. It takes all the character models, assets and environments and puts them together in a way that makes it look as if they are all a part of the same scene. This also includes overlaying text and titles.