All of Gavagai's services build on a core system called Gavagai Living Lexicon which continuously learns languages by ingesting newly published texts from the Internet. In this process the lexicon learns about the vocabulary of the language and the relationships between words and multiword expressions. From this understanding we can extract useful information in our services. For more information about the living lexicon see: http://lexicon.gavagai.se/.
In Gavagai Explorer, you can see the effects of the living lexicon that is working in the background if you look for suggestions of synonyms in each topic. Each synonym suggestion is taken from the knowledge we have of relationships between words. You can also look for multiword expressions (like 'san francisco') which are built automatically from the systems general knowledge of language.
You can have a look at the tutorial for the previous version of Explorer for tips on how to do things: http://gavagai.se/blog/2016/01/25/getting-started-with-gavagai-explorer-2/. This tutorial will be updated for the new version in the near future.