I want to understand what mounting is. It is used in different contexts and situations and I can't find resources which:Describe the mount conceptExplain the actions taken by the computer/OS/utility when a mount is performedHow and in which situations mount is usedWhich features in the Linux mount command are of frequent use and some examples( I hear mount applied to diverse entities directories, flash drives, network card, etc )
understanding mount as a concept in the OS
filesystems;mount
As fschnittpoints out, a comprehensive answer to this would likely be a chapterin a systems administration manual, so I'll try just to sketch thebasic concepts.  Ask new questions if you need more detail on specificpoints.In UNIX, all files in the system are organized into a singledirectory tree structure (as opposed to Windows, where you have aseparate directory tree for each drive).There is a root directory, which is denoted by /, whichcorresponds to the top directory on the main drive/partition (in theWindows world, this would be C:).  Any other directory and file inthe system can be reached from the root, by walking downsub-directories.How can you make other drives/partitions visible to the system in sucha unique tree structure?  You mount them: mounting a drive/partitionon a directory (e.g., /media/usb) means that the top directory onthat drive/partition becomes visible as the directory being mounted.Example: if I insert a USB stick in Windows I get a new drive, e.g.,F:; if in Linux I mount it on directory /media/usb, then thetop directory on the USB stick (what I would see by opening the F:drive in Windows) will be visible in Linux as directory /media/usb. In this case, the /media/usb directory is called a mount point.Now, drives/partitions/etc. are traditionally called (block) devicesin the UNIX world, so you always speak of mounting a device on adirectory.  By abuse of language, you can just say mount this deviceor unmount that directory.I think I've only covered your point 1., but this could get youstarted for more specific questions.Further reading:* http://ultra.pr.erau.edu/~jaffem/tutorial/file_system_basics.htm