According to Investopedia.com a covered call is defined as "an options strategy whereby an investor holds a long position in an asset and writes (sells) call options on that same asset in an attempt to generate increased income from the asset. This is often employed when an investor has a short-term neutral view on the asset and for this reason hold the asset long and simultaneously have a short position via the option to generate income from the option premium."

This is a popular options trading strategy, but most investors do not use it until a broker or someone else tells them about it. However, in this strategy, much like all other strategies, you need to be fully aware of the risks-rewards dynamic that are involved.