What are seasons?

[PuppMaster]

I went through a patch about a year long wherein i didnt play D2 at all. now that i am back, i keep hearing about seasons, "this season this....." "that season that.....". so i have a question

What are seasons? please be descriptive.

[Jackson]

They're probably refering to Ladder Seasons.

http://www.battle.net/diablo2exp/faq/ladder.shtml