protected override void Update(GameTime gameTime)

XNA 3.1 was a groundbreaking framework that democratized game development on Microsoft platforms. While obsolete today, its concepts live on in MonoGame/FNA, and it remains an important part of game development history. Unless you're maintaining legacy code or targeting Zune HD specifically, you should use MonoGame or FNA instead for any new projects.

graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content";

protected override void Draw(GameTime gameTime)