When you swipe right or left on the Android browser’s Address Bar or bottom toolbar, you can switch to the next or previous tab that you have open.

When you swipe down from the Address Bar (up, if you’ve moved the Address Bar to the bottom), you can open the Tab Switcher, from where you can see all your open tabs, as well as access private, recently closed and synced tabs. In case the swipe down/up gesture doesn’t seem to work, make sure you have Enable Address Bar Swipe Gesture toggled on in Settings.