The main objective of this article is to provide a comprehensive picture of existing wave technologies being used for wave energy extraction. The overview will explain their potential and also the challenges wave technologies face. The article will also briefly discuss the benefits of combined offshore wind-wave projects, also known as hybrids. Key factors and impacts on relevant existing wave technologies will be outlined, including capacity factor and capture width. Finally the levelized cost of energy (LCOE) targets for the most promising technologies will be discussed.