A country's hidden ninja village represent a country's military power. There are 5 to be considered the most powerful and influential. Each representing one of the 5 great countries: the Fire Country, the Wind Country, the Water Country, the Lightning Country, and the Earth Country.
Each village is ruled by a Kage, and respresents its country's element type. Meaning a ninja from a certain country will use (in most cases) jutsus which involves his/her country's element. There are 10 countries total. The other 5 being the Sound Country, the Rain Country, the Grass Country, the Wave Country, and the Waterfall Country.