Google Image search by uploading image

I have recently came to know that Google has the facility of searching photos and images by using (uploading) images. To search image in google search you have to navigate to www.google.com in your browser. Then select images. Then the page will be reloaded again.

Now you can upload the an image by clicking on the camera inside of the search box or by typing URL of an image.You can also provide description about the image. Finally hit enter. Then you will get a page like this not this same one. You will get results according to the image you have selected.