The most notable and much awaited feature of Internet Explorer 7.0 is its tabbed windows -- also known as tabbed browsing.
Let's say that you are currently on a website and with want to look at another website. Instead of starting up another instance of Internet Explorer, you can put the second website in a different tab of the same Internet Explorer.
Opening New Tabs
To open another tab, do Ctrl-T or click the empty new tab as shown...
Then type in your second website URL into the blank page that is opened up...
Closing Tabs
To close a tabbed window, you simply click the X icon on the current tab...
or do Ctrl-W.
If you want to close a tab other than the current tab, you can right-click on the tab that you want to close. Then select Close from the context menu.
If you have a lot of tabs open and you want to close all tabs except for one, then right click on the one tab that you want to remain open. And then select Close Other Tabs from the context menu.
Opening Links in Tabs
Normally when you click on a link on a webpage, the destination page will replace the current page. If you want the destination page to go onto a new tab, you click the link while holding down the Ctrl key.
Alternatively, you can right-click on the link and select Open in New Tab from the context menu. This is great when you are on a page with several interesting links that you want to look at later. You simply open them in new window without having to leave your current page. And when you are done with the current page, you got all the link destinations in the other tabs to go back to.
Normally, when you type a new URL into the address bar and hit Enter, the new URL will replace the page in the current tab. If instead you want the new URL to go into a new tab, hit Alt-Enter instead.
source- www.learnwebdesignonline.com