Digital watermarking techniques have been developed to protect the copyright of media signals. This chapter aims to provide a universal review and background about the watermarking definition, concept and the main contributions in this field. The chapter starts with a general view of digital data, the Internet and the products of these two, namely, the multimedia and the e-commerce. Then, it provides the reader with some initial background and history of digital watermarking. The chapter presents an extensive and deep literature review of the field of digital watermarking and watermarking algorithms. It also highlights the future prospective of the digital watermarking.