The size refers to the diameter of the light. The fixture width is the width of the light. The fixture height is the height of the light. The bulb included refers to whether or not a bulb is included with the purchase. The number of lights refers to how many lights are on the fixture. The color refers to the color of the glass. The style refers to the Tiffany style. The material refers to the glass material. The fixture type refers to the type of mount. The feature refers to the fact that it is a semi-flush mount. The voltage refers to the range of voltages for which the light is compatible. The bulb base refers to the type of bulb base required. The light type refers to the type of light that can be used with the fixture.