私は料理が好きてす。 These are terms associated with specific methods of cooking. Sauté cooks large or small pieces of food in a wide, shallow pan in a small amount of hot oil and/or butter over medium-high heat, turning often or just once. Preferably, the butter would be clarified to prevent the butter from burning. The term is derived from French. On the other hand, stir-frying increases the heat to high, and keeps the food in constant motion. The food is cut into smaller pieces so that it will cook quickly. Because of the constant rapid movement, a wok is normally used. Butter is not used because it burns easily at high heat. The oil used would have a high smoke point, such as peanut oil. BTW, there is also pan frying, which uses lower heat and larger portions of food. The lower heat allows the inside to get done without burning the outside.

To saute is a verb, to fry, or 'jump' (from french). To stir fry is to stir as you fry and is associated with Asian cooking. You can also have sauted potatoes but not really stir-fried potatoes.