system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the QR code manages to not be the same with other QR code that has already been generated?

I was reading online and saw an option when I right clicked an image to create a QR Code. I know QR Codes are unique but how do they manage to avoid having the same pattern with the other QR Codes? Does it have a database where all QR codes are stored? I tried searching through this but can't find any similar queries aside from QR codes are unique.
gpt
If you generate two QR codes for the same piece of text or link, you'll get two identical QR codes. They're not randomised or generated out of thin air and then matched with a site or link or something. Rather the QR code itself encodes the information onto it. So as long as whatever you're encoding is unique, the QR code is unique to it. 

The wikipedia page (section 'encoding') actually shows you how it functions.