what do we doublw dot in address bar

The double dot in an address bar usually means .. in a web path, which tells the browser to go up one directory level in the URL path, not to do anything dangerous by itself.

What it does

• ./ means “current folder.”
• ../ means “parent folder.”
• ../../ means “go up two folders.”

Simple example

If the current page is: https://example.com/a/b/page.html then a link like: ../images/photo.jpg usually points to: https://example.com/a/images/photo.jpg

Related things people confuse it with

• In some browsers, an icon near the address bar can indicate site permissions or protocol handlers , which is different from .. in a URL.

• A dot in URLs can also appear for other reasons, like the www. subdomain or email-style behaviors, but that is not the same as .. in a path.

Bottom line

If you saw .. in a URL, it usually just means parent directory navigation in the web address path.