Which is the operational difference between LAF (vertical and horizontal) and RLAF?

Please help, which is the operational difference? I have seen a lot of diagrams and the flow air between them are the same: extract air from the environment then filter and then is inject in work zone, then extract and a percent of air recirculate and the other is eliminate by filter to the environment.

very thankfuly for your comments.

Olga Coaguila

In a a LAF HEPA filtered air is blown towards te operator (thus creating product protection)
In a RLAF (or downflowbooth) downflow air is creating product protection and the inflow ait is creating personal protection. (Means that an exhaust has to be inplace)