Hungarian is an agglutinative language, i.e. affixes are used to represent meaning. Other agglutinative languages include, for example, Japanese, Turkish, Finnish, Eskimo, Quechua and Aymara. Finnish is the closest relative to Hungarian, but this does not mean that if you speak Finnish, you will understand Hungarian, even slightly. The relationship is purely linguistic (and some people doubt even that).  

Sometimes long words are created, cramming a lot of meaning into a little space. Like "Letartóztathattatnálak" is a perfectly regular Hungarian word, meaning "I could get you arrested."