A satellite is something that people have launched into orbit around the Earth. Satellites circle the Earth, either remaining as if they are in the same place as seen from the Earth, called Geostationary orbit, or moving around the Earth.
Satellites are used for many things. They can be used to watch and take photos of the Earth for military or other reasons; they can be used for communications like television or telephones, to find out where you are using Global Positioning System (GPS), to watch and help predict the weather, and for various research purposes.
A sauce is a liquid that is used to add flavor to food. Sauces can be served by pouring them on top of food, or by having them on the side, like the dipping sauce in the picture. Two of the most popular sauces are soy sauce and tomato sauce, or ketchup. Gravy is a sauce made to accompany meat, and chutney is a thick sauce made from spice and vegetables.
Sauces can be any thickness, from really watery to very thick and chunky.