Scripts, Binaries, and plain old text
Everything in UNIX, from devices to documents to processes, is done through files so you can imagine that there are some very weird files. Fortunately, most of the files owned by normal people are either binary or ascii. Binary files are only readable by a computer or application while ascii files may be "computer readable" but also are interpretable by mere mortals.
You can determine whether a file is binary or ascii using the file command. Alternatively you can use more or cat and either the file will scroll by well behaved and readable, or it will generate beeps, yelps, hyroglyphics and possibly mess up your window.
We will get into scripts during the next seminar, but the computer won't recognize it as such without a line like #!/bin/csh or something at the beginning, and it won't know it is executable unless your set the appropriate permissions.