The three main types of fluorescent light bulbs are the T12, T8 and T5. The T5 is also available in the T5H0 model which is a much brighter version of the T5.
Check what type of bulbs the light fixture is able to take. They often require a specific type of bulb, so it is important to check the fixture before making a purchase. The T12 is the original model of fluorescent light bulb. They are the biggest in size and cheapest to buy, but use the most energy. They also only work in an environment that is above 60 degrees Fahrenheit. The newer model, the T8, is slightly more expensive, but it uses less energy. These bulbs also work in any temperature, and they turn on much faster than the original model. The T5 is a smaller version of the T8, but it emits the same amount of light. These bulbs are more expensive than the T8, but they can be great for saving space in places like a desk, a room with a low ceiling, or under a countertop. The T5H0 is the same size as the T5, but emits twice as much light. The T5H0 is best used in rooms with high ceilings and a small number of light fixtures.