Considering which lifts to use but i dont understand the difference between DR4B and RD4B and what they stand for
Double reverse 4-bar, reverse double 4-bar. They’re the same thing.
There are a lot of lazy people, me included, that don’t want to type the whole thing. 
Thanks y’all, i guess i can now be lazy…
I don’t mean to insult you. 
Just think of it as being efficient, using less words for the same meaning!
Oh i was kinda joking, i didnt even read that as an insult
If they are the same thing then which one would be better to use? In a notebook or something.
It doesn’t really matter. You can write at the beginning what is a Double Reverse Four Bar (DR4B)?. Then during the design process and later on, you can write DR4B as long as it’s explained at the beginning.