The Xceed Compression control handles compression and decompression when the source and destination are blocks of memory. The data can be provided in a single block of memory, or in streaming fashion. Encryption and configurable compression factors are also supported. The Xceed Compression control does not work with zip files at all. All zip and unzip tasks involving files and are handled by the Xceed Zip control. Both the Xceed Compression and Xceed Zip controls are part of the same library file (XCEEDZIP.DLL), and can be accessed by either the ActiveX interface, or by direct DLL API calls.
The Xceed Zip compression control uses the same compression algorithm that is used for zipping to and from zip files, but does not include the same type of information in the compressed data. When you compress data with the Xceed Compression control, the data does not have any file or date information embedded into it, nor does it contain local headers, a central directory, and other zip format related structures. The compressed data is almost pure raw compressed data. The only overhead added to the data is an encryption header (when applicable) and a 32-bit checksum that is used when uncompressing the data to ensure there are no errors.
XceedSoftware.XceedCompression.6