Earlier quoted context omitted.
So mosaic, for example, was just a fad?
The concept was not a fad. The concept was an advance which has lived on in other browsers. With imagination perhaps, one could even apply the paradigm of a browser to mechanical and biological domains ("non-computing" in a software sense). concepts vs. tools for strategic business and market advantage
IMHO
1) interpreting of tags
2) sending the tagged content at a site, to an enquiring browser so that in a virtual sense, one is visiting the location.