Gmail’s new Inbox is rolling out for all users, it won’t be turned on by default though. You need to check and enable it by selecting ‘Configure inbox” from Settings (Gear) menu and then need select two other (optional) tabs- Updates and Forums- and click on “save” button to view Gmail inbox with tabs.

Hiding tabs in Gmail: Gmail by default, offers Primary, Social and Promotions tabs. By clicking on + sign on right, you can able to hide or show tabs in inbox. 

Disabling Gmail inbox tabs: Don’t like tabbed inbox, you can disable it easily.

Hover over Inbox on left and from drop down menu you can select and change to other inbox type- Important first, unread first, Starred first and Priority inbox-before enabling Tabbed inbox we’re using Priority inbox, so you need to chose it.

Switching to priority inbox from tabbed inbox Gmail