A file with a .cbr extension is a collection of images stored as compressed binary files using the RAR compression file format. It contains images in JPEG, PNG or GIF images that represent images in a comic and are shown to user when the file is used in ebook readers such as Calibre. CBR is similar to CBZ other than that CBZ is compressed and stored in the ZIP file format. These files can be contained inside comic book collection files such as CBC.
CBR File Format
A CBR file is a RAR archive that is stored as a binary file to the disc. The images inside a CBR file are stored and displayed to users in an ordered manner when opened by an ebook reader. CBR files can be decompressed using any decompression software that supports RAR file format. However, images decompressed this way are not in the same order as they appear in the visual display when opened in reader software.