Depending on how old your house is, the older houses mainly used Bayonet light bulbs. This bulb looks just like your average bulb except for the connection point. The connection point has 2 points which stick out to either side of the connection which connects to the power on either side of the socket connected to your light connection. These are becoming outdated in new houses as the connection points dont always make proper contact with the power points inside the light connection and when it is not connecting properly, the bulb is quite likely to blow, costing you more time and money to get a new one.
Screw–in bulbs are the more commonly used bulbs today, especially in newly built houses. The connection point looks like a big screw which you will insert into the fixture point and screw it in. This helps for a much better connection of power to the bulb and lasts longer than the Bayonet type bulb.
Ceiling light bulbs are different. They are smaller in size and the connection point has 2 points that stick out at the bottom of it. The light itself looks conical so that it sits flush with your ceiling once you put the bulb in. these bulbs only use a small amount of electricity and usually last a long time.
These are sometime used inside your house but rarely, they are mainly used outside for your spotlights. They are shaped like a thin tube and use quite a bit of electricity to warm up but once they have warmed up, they tend to use much less electricity. These bulbs produce a sharp strong light which enables you to see far distances into the dark. Always remember though, the stronger the wattage of the bulb, the more energy it uses and the brighter it is but, you also need to make sure that your connection can handle a higher wattage or the bulb will blow. Check the marking on the spotlight to see which is the most wattage bulb to use.
There is a considerable difference between Compact Fluorescent Lights (CFL) and Tungsten Lights. These light bulbs differ from the normal Incandescent Bulbs, which glow by heating a tiny coil of Tungsten wire.
These light bulbs glow using Mercury Vapor and are a very energy efficient way to light certain areas of your house. I say certain areas because these bulbs are only really cost effective when used in lights that stay on for 3-4 hours or more at a time. Here are some interesting facts about these bulbs: