How is google search by image implemented?

Question

I can just drag and drop any image in google and get results. :)

How is it implimented ? What is the idea behind the algorithm ?

Is that image data converted to

Answer 1

Surprisingly, we can also use Google to answer this question!

What is the algorithm used by Google Search by Image

It is definitely not confirmed, but I'm sure Google uses many of these techniques/ a blend of them when identifying images