To begin with I should say that Apple products have not been the subject of my professional interests before. I got accustomed to MS Windows and Linux, which I mostly had to deal with. That is why I needed some time to understand the principle of Appleās operation. But as soon as I realized that Mac OS was based on the well-known UNIX, everything became clear for me. It must be said that Mac OS has a lot in common with the Unix. For example, the hierarchy of the file system, network services (guided by Samba), print manager CUPs and some other programs and principles.