this type of search where you search for similar images by supplying an image is called Reverse image search.
Google image search has this feature , to use it just click the camera icon in the search bar , doing so will open an input box where you can enter the URL of the source image , or you can use the Upload an image option to use an image you have on your computer . once your file is loaded you will have your results in a similar way to the screenshot displayed below.
I searched an image from the Classic Doctor who series and the image search found me some pretty relevant results . as you can infer from the screenshot the search not only uses your image but it guesses some keywords for you , all said and done this is a very quick way to find images on the internet . There, hopefully that helped.
if you want to read up more on this topic you can always ask Me in the Comments or Google :)