Where I can get more information about the above modules?

- Sprite is a piece of texture that can be placed into the 3D space and always faces towards the camera.
In most cases sprites are used in particle systems as pieces of smoke, sparkles, flames etc. In these cases you use the Sprite Particle module connected to a Particle Source module.
But in same cases you might want to place an individual sprite int the scene that persists. The most common usage is displaying a glow or lens flares of a light source. In the cases you use the Sprite module.

Sprites can be assigned to different layers that determine the sorting of them.

Background sprites are displayed behing all other sprites.
Sorted sprites are displayed in front of Background ones, but also sorted among each other based on their distance from the camera. Sorting can be CPU intensive if you have lots of sprites, therefore only use this layer when absolutely necessary (for e.g. smoke pieces).
Foreground sprites are displayed in front of Sorted ones.

Backround, Sorted and Foreground sprites are all subject of covering by scene objects based on their spacial position.

Flare sprites are displayed in front of all objects in the scene. In other words they are never covered by any object regardless of their position. They are typically used as lens flares (star effect, anamorphic streak etc.) that always appear in front of all.
Reflection sprites can be used for lens reflection effects. These are colored rings lining up along the diagonal of the screen. Via the Refl Position property you can set the distance of the sprite from the actual position along the diagonal.

- Occlusion Detector is a special kind of sprite. The sprite itself is not visible, but you can measure how much of its shape is covered by the scene objects. For e.g. you can use a disc shape to measure of the coverage of a light source, then use this to control the visibilty of different parts of your flare effects (the balance of the background and the lens flare parts of the effect).

In the Common library you can find a series of Sprite_Flare_*.xcomp files which implement different complex lens flare effects using a series of sprites along with occlusion detection.
In the next release we'll add an example of these among the tutorials. Until then please download and install this:
https://mab.to/WQnr1HsiT
The file name is Sprite - 01 - Lens Flares + Occlusion.xcomp.

- Pipeline and Blob Section are obsolete modules only used in the past for experimental things, they will be removed.