Features Of 7 ZIP
Bruce Parker
About 7 ZIP
By default, 7-Zip creates 7z-format archives with a 7z file extension.
Each archive can contain multiple directories and files.
As a container format, security or size reduction are achieved using a stacked combination of filters.
These can consist of pre-processors, compression algorithms, and encryption filters.
The core 7z compression uses a variety of algorithms, the most common of which are bzip2, PPMd, LZMA2, and LZMA.
Developed by Pavlov, LZMA is a relatively new system, making its debut as part of the 7z format.
LZMA uses an LZ-based sliding dictionary of up to 4 GB in size, backed by a range coder.
The native 7z file format is open and modular. File names are stored as Unicode.
In 2011, TopTenReviews found that the 7z compression was at least 17% better than ZIP, and,
7-Zip's own site has since 2002 reported that while compression ratio results are very dependent upon the data used for the tests,
"Usually, 7-Zip compresses to 7z format 30–70% better than to zip format, and 7-Zip compresses to zip format 2–10% better than most other zip-compatible programs."
The 7z file format specification is distributed with the program's source code, in the "doc" subdirectory.
Features of 7 ZIP
⦁ Open architecture
⦁ High compression ratio
⦁ Strong AES-256 encryption
⦁ Ability of using any compression, conversion or encryption method
⦁ Supporting files with sizes up to 16000000000 GB
⦁ Unicode file names
⦁ Solid compressing
⦁ Archive headers compressing