A DJVU file is a digital document format that is designed for efficient storage and transmission of scanned documents, photographs, and other images. This file format was developed by AT&T Labs in the late 1990s and is currently maintained by LizardTech, a subsidiary of Celartem Inc.

The main advantage of DJVU files over other common file formats like PDF or JPEG is their compression algorithm. This algorithm is specifically designed to handle high-resolution images with fine details, such as text or line art, without sacrificing image quality. As a result, DJVU files are typically much smaller in size than similar files in other formats.

DJVU files also support various advanced features, such as layer separation, progressive loading, and bookmarking, which make them a popular choice for digital libraries, archives, and other repositories of large volumes of documents. In addition, DJVU files can be easily converted to other formats like PDF or TIFF, making them compatible with a wide range of software and devices.

To view and manipulate DJVU files, users can either use dedicated DJVU viewers or plugins for popular document viewers like Adobe Acrobat or Google Chrome. Some notable DJVU viewers include SumatraPDF, STDU Viewer, and WinDjView. These viewers allow users to zoom in and out, rotate, search, and extract pages from DJVU files, as well as to convert them to other formats.

Despite its advantages, DJVU files are not widely used or supported outside of specific fields like science, law, or engineering. This is partly due to the popularity of other file formats like PDF or JPEG, which are more versatile and compatible with a wider range of software and devices. However, for those who deal with large volumes of scanned documents or images on a regular basis, DJVU files can be a valuable tool for efficient and high-quality digital storage and distribution.