Zamzar is an online file conversion service that allows users to convert various types of files, including documents, images, audio, and video formats. It supports a wide range of file types, making it easy for users to change files from one format to another without needing to download any software. The service is user-friendly and operates through a simple web interface. Users can upload their files, select the desired output format, and receive the converted file via email or download it directly from the website. Zamzar is popular for its convenience and efficiency in handling file conversions.