Lycos is piling database on top of database. The idea is to give the most relevant results first, not based on relevance ranking of hits, but on a relevance ranking of databases. For the general public, probably not. But for professionals trying to search expeditiously and intelligently, it is important to understand the sources of the content and the possible limitations of those sources. There are several lessons to learn from this example.
Search results can and often do come from multiple databases.
The underlying databases delivering those results may change in part or even completely from one time to the next. The order in which the results from various databases are presented can change. And results from two separate databases may be presented without differentiation. Moving onto the Lycos-owned HotBot there is another multiplicity of databases, but some of them are different. Looking at the top page for HotBot, and for most other search engines and portals, can help identify other additional databases.