Google Chrome browser give you option to PIN a tab. This PIN is different from windows 7 taskbar PIN.

What is Google Chrome PIN Tab feature
Google Chrome’s Pin Tab is a very helpful feature is you keep some webpage / websites open for longer duration. Like you may be keeping your Facebook, Twitter, Google Plus account page open for longer duration. You can PIN such webpages. After you PIN any tab, it will shrink down to web site’s favicon width. The pinned tabs will move to extreme left of the tab bar.
Below screenshot will help you understand better
Tabs before pinning (click on image to enlarge)

Tabs after pinning (click on image to enlarge)

How to PIN a tab in Chrome browser
This is very easy. Simply right click on tab and select Pin tab

How to UNPIN a tab in Chrome browser
Right click the pinned tab and select Unpin tab

The pinned tab will be deleted after you close the chrome windows. This is not permanent.
Pinning on the left seems odd, or at least redundant. If you put the tab on the far left, it will always be there. For me, it seems like pinning a tab to the right side of the browser would be vastly more useful. I often open links in new tabs that I do not have time to look at right then, and want to save for later. This can fill up quickly, and by virtue of being at the newest tab, you’re all the way on the right and have to move all the way back over to the left. If you had a “pin on right” option, you wouldn’t have to do anything; you’d be right there!
Maybe my explanation doesn’t resonate with you, but at the very least, I wish there was an option to pin on the right.