A web catalogue (or web directory) is a curated list of websites grouped into categories by human editors, letting people browse sites by topic instead of searching. Once central to how the web was discovered, most general catalogues have faded — though niche and local ones still hold value.
In the web's early years, before search engines were reliable, directories like the Yahoo Directory and the volunteer-run Open Directory Project (DMOZ) organised the internet by hand. An editor reviewed each submission and filed it under a category — "Arts > Photography > Techniques," for example. For years a listing meant real referral traffic and a valued backlink, which is exactly why low-quality submission directories later multiplied and were eventually devalued by search engines.
General-purpose catalogues no longer drive rankings, and mass-submitting to hundreds of them is a spam signal, not a strategy. But a well-run directory in your industry or town can still earn a relevant link and genuine visitors. A Toronto dental clinic listed in a respected regional health directory, or in the local chamber of commerce, gains both a citation and a bit of credibility.
For local businesses, the more productive descendants of the catalogue are consistent citations built through local SEO and a maintained business directory presence.