What is full form of a in rgba---red green blue_____?

Answer 1

alpha - which is opacity.

Answer 2

Alpha write on 0 to 1, e.g. 0.1 = 10% opacity

Answer 3

oh got it

Answer 4

Hmm... Like when you set alpha to 255 image becomes full transparent (like glass, you will be able to see through it :D)