The protection and enforcement of intellectual property rights for digital media has become an important issue in many countries of the world. There is increase in the popularity and accessibility of the Internet to record, edit, replicate and broadcast multimedia content which has necessitated a high demand to protect digital information against illegal uses, manipulations and distributions. Digital watermarking technique which is the process used to embed proprietary information into multimedia digital signal provides a robust solution to this problem. This paper reviews different aspects and techniques of digital watermarking for protecting digital contents. It also explores different application areas of digital watermarking such as copyright protection, broadcast monitoring, integrity protection etc.