No problem.
Go to Google Image Search.
See the little camera icon at the end of the search bar? Click that.
Now you'll have an option to either paste the image URL (what I just did!) or upload the file (if you have it on your computer).

Once you do that and hit Search, Google tries to match your image up with whatever it can find. If it finds enough info it can even sometimes "guess" at what's in the picture, and give you relevant website results! :D