If you see a lock button next to a website's address in Microsoft Edge, it means:
What you send and receive from the website is encrypted, which makes it difficult for anyone else to get to this info.
The website is verified, which means the company running the site has a certificate proving they own it. Click the lock button to see who owns the site and who verified it.
While a gray lock means that the website is encrypted and verified, a green lock means that Microsoft Edge considers the website more likely to be authentic. That's because it's using an Extended Validation (EV) certificate, which requires a more rigorous identity verification process.