How do i play multiplayer from battlefield 3 ?

My bro has just bought a battlefield 3 blue ray disc for my PS3 and he will give it to me at christmas.

I can't wait to play it on multiplayer, so I open youtube and I see people making vids about the multiplayer gameplay and I think it's great.

But when I see the video about the campaign mode ( from other people's youtube channel ) he started at the main menu and at the main menu I don't see any multiplayer. Its only :

Campaign

Options

Credits

Quit

I think its from a PC platform. Can anyone tell me the main menu of the battlefield 3 for PS3 ? Do I need to complete campaign first ?How do i play multiplayer from battlefield 3 ?
He had it on Xbox. The Xbox came on two discs, one for campaign, and the other for multiplayer.



The PS3 version puts all of it on one disc, and it's all in one menu:



Campaign

Co-op

Multiplayer

My Soldier

Options

Extras



So yeah. Don't worry about it. And no, you don't need to finish campaign first. That would be terrible.How do i play multiplayer from battlefield 3 ?
There are 2 disks one for multiplayer and one for the campaign.