In the digital era, the production and distribution of multimedia content—ranging from text and software to images, audio, video, and databases—occurs entirely through digital means. While this shift brings benefits such as noiseless transmission, flexible processing, and system reconfigurability, it also introduces significant security risks. Digital assets shared over the internet are vulnerable to unauthorized access, tampering, and distribution, often resulting in financial and intellectual property losses. Moreover, establishing true ownership becomes challenging when content is misused. Digital watermarking has emerged as a widely adopted solution for copyright protection and data integrity verification. This paper explores the role of watermarking as a security tool for both multimedia content and relational databases. Unlike traditional media watermarking methods, relational databases pose unique challenges due to their structure—composed of tuples with independent attributes. The study examines various watermarking techniques, evaluates their robustness against common attacks, and highlights emerging trends and applications. It further distinguishes between multimedia watermarking and database-specific approaches, offering insights into their adaptability, security trade-offs, and future research directions.