CFL stands for compact fluorescent light. Although you can purchase CFLs at nearly any hardware or construction store, they are not optimized for growing plants. Plants thrive better in certain spectrums of light, which most normal CFLs simply won't provide. Plants prefer blue spectrums of around 7000K for the vegetative and propagation phases.
Our CFLs are specifically designed to be used for growing plants and are optimized for this purpose. This means that for every kWh of energy used, a much higher efficiency of this energy will reach the plant's leaf surface and be converted to food and growth. CFLs are a great place to start for new hydroponic growers and are great for propagating new plantlets. They are cheap, emit very little heat, and offer the best spectrum for stimulating vegetative growth.