The results shown in a browser after a search are generated on the basis of the data previously collected and indexed in a database. Despite a common misconception, a search engine does not explore the Internet every time the user sends a query. The NEToskop database contains only pages from Polish WWW servers. A search engine does not require human input. On the other hand, a catalogue is always created by people who seek interesting WWW sites, describe their contents and group them into thematic categories.
Catalogues tend to contain much fewer addresses.
It depends on the information that you are searching for in the Net. Correspondingly, if you cannot predict the thematic category under which the desired data might have been catalogued, or if the data is not common, or you want a selection of pages longer than those which may be found in catalogues, then you should use a search engine. Poland-based search engines typically only index pages located on Polish servers. Consequently, they contain data about the majority of Polish WWW pages. Even the smallest Polish search engine is likely to have collected more Polish WWW pages than the best foreign ones.