An epub file is a digital publication format that can contain text, images, and other multimedia content. It was developed by the Open eBook Forum, an organization made up of publishers, manufacturers, software developers, and online retailers. The name “EPUB” stands for Electronic Publication.
The EPUB file format is designed to be a universal file format that can be used on any device or platform. It supports reflowable text, which means the text can be resized and optimized for different screen sizes. Additionally, it supports multimedia content such as audio and video files, as well as interactive elements like quizzes and games.
EPUB is widely used by publishers to distribute their ebooks online. It’s also supported by many popular e-reader devices, including Amazon's Kindle, Barnes & Noble's Nook, and Apple's iPad.