Four starts a year
Japanese TV anime begins in four seasons: winter in January, spring in April, summer in July and fall in October. A season of twelve or thirteen weekly episodes is called a cour.
On Anime1
The Season column of the anime list shows when each series began, and the Winter, Spring, Summer and Fall shelves gather them.
Longer runs
Some series run for two cours or more, such as The Beast Player Erin with fifty episodes and MÄR: Märchen Awakens Romance with more than a hundred.