Solid compaction is a special compressed storage format, and solid compaction compresses all files to be compressed as a continuous stream of data to be processed. Popular can think of this: ordinary compression is a file of a file is compressed and then synthesized compressed package, solid compression is the first to connect these files as a large file for compression. The advantage of this is that the compression rate is higher when compressing large volumes of small files, and the compressed file size is smaller. But there is also a drawback is that even if you only open one of the small files, you need to extract the entire compressed package. In the actual use, as long as you need the minimum volume of compression, as far as possible to use 7z solid compaction, the disadvantage of the actual effect is very small. Currently compression in the right-click menu "Add to ***.7z" is the default solid compression, directly with this menu item can be used to press out a fairly small file. You can also select "Compress rate First" in the "you will create a compressed file" screen or set the compression format to 7z in custom, and tick the "Create Solid compressed file" option to achieve 7z solid compaction. (Note: All zip Compressed files are always non-solid, so the zip compression does not support solid.) )