Cách sử dụng
A watermark is a special kind of pattern or design that is added to paper or digital documents to prove that it is an original, authentic copy. It can be seen as a light or dark mark that is visible when the paper is held up to the light. Watermarks are often used on important or sensitive documents like certificates, contracts, or photographs to prevent them from being forged or copied illegally. They can also be used on digital images or videos to indicate ownership or copyright. So, if you see a pattern or a mark on a paper or digital document that is lighter than the rest of the material, it is most likely a watermark.