Answer:
Watermark
Step-by-step explanation:
This is actually called a Watermark. It is usually used as a way of showing the name or logo of the author who owns the content that is underneath the watermark. This is done so that individuals cannot steal the owner's work and use it as their own. Usually, the owner has the original version of the content without any watermark, as well as individuals that have purchased the content or a licence to use the content for personal or commercial usage.