You may be referring to TOGA? "TakeOff and Go-Around" thrust.
Basically your maximum power available for takeoffs or "going around" (aborting a landing).
There are certain climb gradients an aircraft must achieve when taking off etc to avoid hitting terrain and obstacles. These are based on using max power.........not always, but generally speaking.
Does that answer your question?
The gradient expressed in a % can be converted to a climb angle and also a rate of climb (based on your ground speed).
ie: a 5% gradient is approximately 3 degrees. If you multiply your ground speed by the % number you get a rough required rate of climb to clear obstacles...........eg: 5 x 120kts = 600fpm (feet per minute).
The various certified minimum limits vary WRT how many engines you have 2, 3 or 4 and at what stage you are during the takeoff.