The book "World of Skills" (828 pages) is an answer to a straightforward question: What skills make citizens of a country the best in the world? We can all agree that everybody is good at something. If you want to advance your career, you should invest more time in learning and practicing something in which you have already proven to be good at. You therefore work on developing your skills and eventually become the best in your territory. The same goes for countries. They should firstly identify skills which make them the most competitive in the world, so that they can invest more in those skills (in people and companies) to create growth in areas in which they have already achieved success."World of Skills" presents an original collection of knowledge graphs for 190 countries as the culmination of more than a decade long research project by Dr Sinisa Grgic. Each graph represents the skills of citizens that make their countries the most competitive in the world. Such skills are then grouped into skill-clusters (by modularity, or density) and presented in the form of a network. The only way to benchmark a particular country to the rest of the world is to collect sufficient data for the entire world. For meaningful comparisons to be made, no individual country can be benchmarked globally, against itself. They must be measured against a major and significant collection of relevant data. The dataset used for this research was compiled from a vast collection of publicly available online sources, anonymized and translated from dozens of languages into English.One of the expected, but still surprising discoveries is presented in a graph on the cover - a social network of countries by shared top skills. It shows a world that has not been seen before.