When you Archive a Drawing, you create a permanent copy of it. Later, you can reproduce it as needed or just refer to it in your research. If you printout your survey map or plat and store it in a job folder, that's an archive. If you file the survey at your local county office, that's also an archive or 'record' of the survey.
When you archive a drawing file, it is important that the file format be as 'software independent' as possible. In other words, how will you open the file years from now if you no longer have the software that created it or a computer that software can even run on. This has been a common problem as computers, operating systems and software have evolved over the past 20 years.
You will also want to archive using a vector file format as opposed to a raster format. Vector formats store the commands to re-create the drawing regardless of output size. So if you originally archived an 18" x 24" drawing then reproduce it on an 8.5" x 11" printer, the drawing will look perfect, even though it is a different scale.
If you include a scale bar in your drawing, the scale of the drawing can be ascertained regardless of what size output is re-created from the archive.
TPC recommends archiving your drawings as PDF or PNG files. Both are vector file formats that are not created or controlled by MicroSoft and therefore are not even Windows dependent.