The Strip Archive of a webcomic is, at its simplest, a collection of the previous strips which are kept on line for the readers to read. While some premium series may charge a fee for archive access (either being only available to paying customers, or having just the most recent strip viewable for free), most series allow free access to the archive. The only stipulated limitation is that the reader not archive the strips separately, since many webcomics depend on banner ad hits for supplemental income. This is requested on the honor system, being otherwise unenforceable, but it's usually not worth bothering with for those who would break the rules.