Before graphic user interfaces (GUIs) were invented, access to computers was limited to text-based terminals. The computer was controlled through a series of “commands”, or a command line interface (CLI). For example, rather than moving a file from one location to another by dragging it, one would type:
mv filename.txt /path/to/new/location
Our servers run a variant of Unix (FreeBSD), and it is primarily controlled by this very mechanism. We provide access via a telnet or secure shell, so that our users may manipulate files, run programs, etc. through a command-line interface. Some users prefer or require this; others may have never even heard of it. The majority of users who primarily use our services for website and email hosting will not require shell access.