Reflections come in two forms:

• Reflection environments: A good example of a reflection environment is a 2D image map being used in a simulated spherical reflection. To create a spherical reflection from an image, begin by adding a sphere_map node (located in the Node menu's Lighting>Environment Map category) and attach it to the root node's Reflection_Color input. Next, add an image_map node (in the Node menu's 2D_Textures category) and connect it to the node's Color input. Finally, select an image to use by clicking the Image_Source input's file name (set to None by default). You may also use any 2D or 3D texture in place of an image map in the manner described here to create interesting effects.
• Ray traced reflections
: To enable ray traced reflections, begin by creating a reflect node (found in the Node menu under Lighting>Ray Trace) and attach it to the rott node's Reflection_Color input. To best simulate your scene, you might want to set the Reflectnode's Background input to use the same color (or texture) as your actual scene background (you can click the Background input's color then drag over your scene to select a color).

NOTE: To use ray traced reflections, you must also check the Raytracing on checkbox on the Render Options window.