Fixed Width text files are special cases of ASCII or UNICODE text files where the format is specified by column widths. Column widths are in units of characters. So if you have data in a text file where the first column always has exactly 8 characters, and the second column has exactly 6, the third has exactly 6 (and so on), then you have a fixed width text file.
Typical Fixed Width Text File
A typical Fixed Column Text file, where the first field is said to be 8 characters, 2nd field to be 6, third field to be 6, 4th field to be 7, 5th and 6th fields to be 8, would look something like this:
