You can also use it to copy entire directories, with wildcards, etc. See man scp for details. To transfer files from your home or office computer to cattell, or vice versa, kermit is sometimes useful. If you have never transferred files before, it is usually the easiest thing to get working. It is slow, though, so, if it doesn't work right away, it is better to try something else rather than fuss with it.
Files can be text, programs, anything.
The way to do that depends on what software you are using. If you are using Procomm, the PgDn key will get you started. To send a file from your PC to cattell, you first tell cattell to get ready to receive the file, kermit -r filename then tell your PC to send it. In Procomm, the PgUp key will do that. This tells you what to type on the cattell side of the connection.