How come olive oil is considered fat and yet giid for cholesterol ?

Different kinds fat: I know this is confusing! olive oil (particularly extra-virgin type) is rich in "monounsaturated" fat and antioxidants which lower LDL (bad cholesterol) without lowering HDL (good cholesterol) and without increasing triglycerides (bad fat).

Type of fat: Not all fats are detrimental to the vascular system, though they all have similar calorie content. The "saturation", or number of "double bonds" that make the fat susceptible to oxidation, plays a role in whether fats are relatively good or bad. Highly saturated = few or no double bonds, tend to worsen disease. Polyunsaturated fats better. Btw, not directly related to cholesterol levels per se.