What is Rest-Pause?
The rest-pause or rest-pause (it's the same thing) is a technique used to get you to do a few more repetitions with the same weight.
Basically, rest-pause consists of resting for 5 to 10 seconds when you can no longer perform a certain exercise and doing a few more repetitions.
You can repeat more than once.
Example
Rest-Pause
You place 150kg on the dead weight, you do 8 repetitions and you can't do the 9th repetition.
Rest for 5 to 10 seconds and do a few more repetitions, that is, the 9th repetition and possibly the 10th. (Usually 1-2 repetitions, depending on the exercise)
If you wish, after these extra repetitions, you can repeat the process.
Rest another 5-10 seconds and try the 11th and 12th repetition.