What is the difference between LED and incandescent lights?

Incandescents tend to be less efficient and use more electricity. A lot of the energy used tends to be converted to heat, rather than light. Fluorescents tend to give you more light for the buck! They run less hot, which tends to mean that more energy is being converted to light, rather than heat. Compact fluorescent bulbs (CFBs) are a good alternative to incandescent bulbs. They have the same type of sockets, so no rewiring is needed, and they cost much less to use while giving out the same amount of light. Their price is going down substantially, and most use very little, if any, Mercury.