Direct mail is a broad term that includes the following types of mailed promotions: Institutional direct mail serves to promote the name of the publishing house with no reasonable expectation of sales revenues.
touch (Unix) touch is a standard Unix command-line interface program which is used to update the access date and / or modification date of a file or directory. In its default usage, it is the equivalent of creating or opening a file and saving it without any change to the file contents.
Why use the terminal? Under Linux there are GUIs (graphical user interfaces), where you can point and click and drag, and hopefully get work done without first reading lots of documentation. The traditional Unix environment is a CLI (command line interface), where you type commands to tell the computer what to do.