In Pokémon Go, your hard-caught Pokémon always have the opportunity to become a better form of themselves. Each Pokémon has a different CP, or Battle Points, which is a basic way to determine its usefulness in battle against other Pokémon. The higher your CP, the more likely it is that your Pokémon will fight valiantly.
When you catch a Pokemon for the first time, you will notice its CP rating. If a friend nearby catches the same Pokémon in their deck, the CP is very likely to be different. For example, a Horsea you caught showed 50 CP, but the same Horsea for your friend might be 23 CP. The starting CP depends on the level of your trainer, but the power-up will always remain the same between the two of you.
If you have enough specific candy and stardust for your Pokémon, you can select power up from the Pokémon menu. Both can be acquired by catching Pokémon, completing research tasks, and other in-game activities. Powering up is basically equivalent to increasing a Pokémon's level in mainline games and will increase CP of the selected monster while giving it a slight increase in health. Your Pokémon will have a limit to its CP, depending on which Pokémon it is and its distance in the evolution chain. Once you reach Trainer Level 35, the CP limit will be removed, and Pokemon can be powered as much as you want, as long as you have the necessary Stardust and Candy.
Each Pokemon you have will have its own power-up level which will determine how much CP you gain per power-up. This hidden number is determined based on your Pokémon's stats you see when you rate it and that species' catch rate. Each power-up increases the power-on level by 0,5, up to the player's coach level plus two.
After every fourth power-up you do on a specific Pokémon, the necessary stardust will increase. Once the required stardust reaches 5000, the increase in CP and HP will decrease, making power-ups less important. As your Pokémon reaches higher CP levels, the candy needed to power up will also slowly increase, but not as often as the stardust increases. If you want a full table showing how much Stardust and Candy is needed per power-up, check out the table below. To keep things simple, the more you power a Pokémon, the more stardust and candy you'll need, and the less CP and HP you'll gain with power-up.
