An End User Licence Agreement (EULA), also known as a software licence agreement, is a document in which someone purchases the rights to use a computer program, software, or application under specific terms and conditions that are set out by the software vendor or publisher.
A EULA often appears as a popup before or after you've downloaded a program or installed an update on your computer. However, some software may be sold with a physical copy of a licence agreement at a retail outlet or through mail order. In this case, the agreement may come into effect once you’ve opened the package or installed the program.
Whether the EULA is in digital or physical form, the agreement is important for software developers who want to maintain some control over the use and distribution of their product.