Comic book or paperback RAR file (decompress with RAR utility)
CBR files open in dedicated readers such as Comical. A CBR file can also be opened by Winrar but will not be displayed as a comic book in paired pages as when viewed in a dedicated reader.
Learn more about files:
Download Comical at Sourceforge.net.
Visit the RARLabs webpage.
Ask a CBR-related question at IT Knowledge Exchange.