Can anyone tell me the difference between p1db and output power ?

Read here:
http://answers.yahoo.com/question/in...5070218AAbqODX

Read also this:
http://www.microwaves101.com/encyclo...ssionpoint.cfm

P1dB represents a compression point of the output power, when the output power is...output power.

For a linear amplifier, only the region of the output power below P1dB is important, when for a non-linear amplifier also the output power above P1dB (in compression) is taken in consideration.

So when I am looking at linear power amplifier - I will have the P1dB parameter
and
For other I have the general output power ?

(generally, I don't see these two parameters together)

Did you read this?