Shi'a Muslims: What is this I saw I satellite T.V? Ahmadiya?

So, yesterday I was watching satellite T.V and I accidentally stopped on an Islamic channel (I normally only watch MTV channels or MBC Persian not this sort of stuff). I saw a bunch of people and there was this Sheikh standing in front of them and he was saying some words like "God make us faithful to Khalife till the judgment day and he was saying things about Ahmadiya" and the other people were repeating what he was saying. What is Ahmadiya? A sect or something? Anyway, as soon as I heard the word "Caliphae" I said "Bullsh*t" and changed the channel. What is Ahmadiya?