7-Zip -- 7z.exe | 7zG.exe | 7zFM.exe (which one to use?)

7zFM.exe is the main file you want

• Technically this is the "File Manager", but I would generally describe this as the "7-zip application"
• Use this .exe if you want to open a .7z (or other) archive, explore it's contents, extract all or some files/folders
• Use 7zFM.exe when double-clicking a .7z file and Windows asks you to choose a program ("How do you want to open this file?")

7z.exe is the command-line version of 7-zip

• Use this .exe when you want/need to use 7-zip via the command-line
• You could call it a more ‘powerful’ version of 7-zip (you can set quite specific parameters via the command line), however there is no GUI (graphical interface) – double-clicking 7z.exe won't open anything

7zG.exe can probably be ignored by most users, but is useful in a few (more adv.) situations

• This is the "GUI module" (which admittedly didn't mean a lot to me at first), but in essence is a second command-line version of 7-zip, but this one will display a GUI (visual) progress/output
• The best way to explain this, and the difference between the main command-line app [7z.exe]…

Imagine you have a 100MB 7-zip archive (one that will take a few seconds to extract), and run the two below commands:

• 7z.exe x MyArchive.7z -r -o – Extract the archive, progress/messages will be shown in the console
• 7zG.exe x MyArchive.7z -r -o – Extract the archive, however there is no output to the console, instead a progress window will appear (with a progress bar, time remaining, etc), as if you had extracted the archive from within the 7zFM.exe application.