Two different ways materials fail over time — and neither one is a simple overload.
A part can fail years into service without the load on it ever changing, and without the load ever cycling. Those are two entirely different failure stories, and engineers routinely mix them up because both involve "damage that builds up slowly." Creep is slow, permanent stretching under a constant stress, driven by temperature-activated diffusion inside the material — it only matters when things are hot. Fatigue is crack growth driven by a repeated, cycling stress — it happens at any temperature, including room temperature, and has nothing to do with how long a steady load has been sitting there. Picking the wrong one when diagnosing a failure means picking the wrong fix.