Final answer:
Watermarks and licenses are intended to protect a copyright holder from unauthorized use. They serve to indicate ownership and set the terms for legal use of copyrighted material, respectively.
Step-by-step explanation:
The intended mechanisms to protect a copyright holder from unauthorized use are:
- Watermarks: Often used in images and videos as a visible, sometimes translucent, mark that indicates ownership.
- Licenses: Legal agreements that permit certain uses of the copyrighted work while restricting others.
Of the options provided, 'Filters' and 'Downloads' are not mechanisms designed to protect against unauthorized use. Filters are typically used to modify or enhance content, and downloads can be both authorized and unauthorized, depending on whether they comply with copyright law.
Copyright protection is essential for the economic rights of creators and prevents others from copying, distributing, or otherwise infringing on the original works of authorship. This protection commonly lasts for the life of the author plus 70 years, as per the U.S. Copyright Office.