Compression depends on many factors. You may apply lossy compression to audio/graphics and get a similar file with a lower file size; you may as well use a certain method which requires extraction before display (zip) /or direct ones (jpg). When using file compression -not data compression like jpg- you will then have to chose for a compression method (rar/zip/7zip to name a few). So, the limit will vary according to how much compressed the file will be (in case you have that setting available, depending on the system you use). To summarize, it all depends and the question does not provide much information.
.txt is not a compressed file.
.txt is not a compressed file.
The amount that a file can be compressed by into a zip file depends on the file's type. Text, document, and Excel files can be compressed a great deal, usually in the 80 to 85 percent range. PDFs, JPEGs, and MP3s on the other hand are not easily compressed and usually compress in the 1 to 10 percent range.
Nothing special. But depending on the compression techniques used, it's a wasted effort, since it won't save more space having a compressed file on a compressed file system.
An image file type that has already been compressed is a jpeg.
No. A copy remains in compressed form.
You can identify it easily in two ways. 1. By its icon, It is a folder up on its side that has a zip through it. 2. By its file extension. Although sometimes these are not always visible, the extension for the average compressed file is .zip . You could also identify if it a compressed file if it says compressed zip folder in grey writing under the file name.
underscore
an image file
No. the format of a file is the description about how the data in it are structured. Thus the data described by the format can be compressed but the format itself can not.
A .tbz file is a tar file that has been compressed using bzip
a ZIP file- it contains one or more files that have been compressed to reduce file size- you have to extract the zip file to be able to see what files are in it