Are the PS3’s or PS4’s comeing out first?

I herd that there having the PS4 come out forst but im not sure??
So are tthe Ps3’s or 4’s coming out first im comfused!!??
I herd it on tv or the radio but idk if its true or not and my brother is in love with thats stuff sooo idk i herd it a couple of months ago and some1 said its comes out next week (the PS4)