The short answer
Creatine monohydrate can improve strength and power during repeated high-intensity effort. It is less useful for endurance and is not a shortcut around training.
If you are considering it
Plain creatine monohydrate is the most studied form; 3 to 5 grams daily is common after any optional loading phase. Early water-weight gain can happen.
Check first
Ask a clinician if you are pregnant, managing kidney disease or taking medicines that affect the kidneys. Supplements are not FDA-approved before sale, so look for credible third-party testing.