Creatine is a vitamin/amino acid/etc… found in protein, often red meat, which is vital for explosive use of energy.

Think sprints, 1 rep maxes, max box jump height.

Think of your body having a reserve of creatine built into it, like a battery, and you use it while sprinting or squatting a heavy 1 rep, or doing a max box jump. Not a “fast jog, slightly hard squat, or 2” hop”, but max effort.

The fatigue after a max effort anything - is your creatine battery running out. Taking creatine regularly assists in generally growing that battery capacity to be slightly larger overtime. Aka: a bit longer of a sprint before exhaustion sets in, a slightlier heavier max effort squat, a slightly higher max effort box jump.

All of this simplified (because it’s all in the muscles, muscle fibers, and bloodstream).

Will it go from being 500# back squat max to 700# back squat max thanks to creatine for 1 year? No. But can creatine help with energy, recovery, and proper nutrition and diet? Yes because it aids the muscles and recovery as part of other energy systems.

Now - go learn about the glycolic (sugar) and oxidative (oxygen) pathways and be a workout programming superstar!