The SpriteA 2D graphic objects. If you are used to working in 3D, Sprites are essentially just standard textures but there are special techniques for combining and managing sprite textures for efficiency and convenience during development. More info
See in Glossary Renderer component renders the Sprite and controls how it visually appears in a SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary for both 2D and 3D projects.
When you create a sprite (GameObject > 2D Object > Sprite), Unity automatically creates a GameObject with the Sprite Renderer component attached. You can also add the component to an existing GameObject via the Components menu (Component > Rendering > Sprite Renderer).