|Internet media type|
application/vnd.comicbook+zip [.cbz only], application/vnd.comicbook-rar [.cbr only]
|Type of format||Multimedia, archive file|
A comic book archive or comic book reader file (also called sequential image file) is a type of archive file for the purpose of sequential viewing of images, commonly for comic books. The idea was made popular by the CDisplay sequential image viewer; since then, many viewers for different platforms have been created.
Comic book archive is not a distinct file format. It is a filename extension naming convention.
The filename extension indicates the archive type used:
Comic book archive files mainly consist of a series of image files with specific naming, typically PNG (lossless compression) or JPEG (lossy compression, not JPEG-LS or JPEG XT) files, stored as a single archive file. Occasionally GIF, BMP, and TIFF files are seen. Folders may be used to group images. Also it may contain optional metadata stored as XML file, the most popular being "Comicinfo.xml" maintained by the Anansi-project. 
Comic book archive viewers typically offer various dedicated functions to read the content, like one page forward/backwards, go to first/last page, zoom or print. Some applications support additional tag information in the form of embedded XML files in the archive or use of the ZIP comment to store additional information. These files can include additional information like artists, story information, table of contents or even a separate text layer for comic book translations.