More than 100 thousand educational films. The resource uses materials created by a huge (more than 8 thousand people) network of "experts" in various fields. Actually it's quite simple to become an expert - just declare yourself as such, choose a specialization and fill in a short questionnaire. Viewers estimate The usefulness of the videos on the usual "five-star" system, which makes it possible to watch the best of them in the category of Top rated.