Executive Clemency: Executive clemency is a broader term that encompasses various acts by which a president forgives, reduces, or commutes (shortens) someone's criminal sentence.
Impeachment: Impeachment is a process by which Congress can remove a president from office for "high crimes and misdemeanors." It serves as a check on presidential power.
Checks and Balances: Checks and balances refer to the system in which each branch of government exercises some control over the actions of other branches, ensuring that no single branch becomes too powerful. The presidential pardoning power acts as one aspect of checks and balances between executive and judicial powers.