There are a couple of ways that files can be offered for download from a web site. The simplest way is to offer the download using a compressed format that not only ensures that the browser will download it rather than display it but which also makes the download as small as possible.
Linking to Downloadable [...]

I have already added a couple of new products to the Member’s Area already this year - one is a free zip program for compressing and decompressing zip files called ViralZip. You don’t even need to sign up for free membership to get that product. The second product uploaded so far this year is a [...]