You can set keyframes for just about anything that has a value, including an object transform, visual attribute, as well as any tool attribute. When you set a keyframe to animate a particular parameter, a function curve is created. The curve is a graph that represents the animation of that parameter over time. You can edit the animation by editing its curve in Animation Editor or by modifying the attribute values in the Tool UI. You can set keyframes manually or automatically—see Setting Keys Manually and Setting Keyframes Automatically.