As you acquire Stardust and Candy in Pokémon GO, you’ll gain the ability to Power Up the Pokémon you’ve caught, increasing their CP and HP.
You acquire Stardust and Candy by catching Pokémon or hatching Eggs.
- Candy is specific to each Pokémon Evolution family.
For example, you obtain Bulbasaur Candy by catching, hatching, or transferring any Pokémon in the Bulbasaur family (Bulbasaur, Ivysaur, and Venusaur). You need Bulbasaur Candy to Power Up a Bulbasaur, Ivysaur, or Venusaur.
- Stardust can be used to Power Up any Pokémon in your collection. For example, you can Power Up a Rattata using Stardust acquired by catching a Meowth. You obtain Stardust whenever you catch or hatch Pokémon of any species.
To Power Up a Pokémon:
- In Map View, touch the Main Menu
- Touch Pokémon
- Select a Pokémon to Power Up from your list of Pokémon
- On the Pokémon summary, touch Power Up
Note: You won’t be able to Power Up your Pokémon until you have enough Candy and Stardust. You can see how much Candy and Stardust is needed to Power Up in the Pokémon’s summary.
Source: Official Pokémon GO support page