- Small pieces of data that websites store on your browser to remember information about you. This can include things like login status, user preferences, and tracking information.
Usually something like .com or .net, plus one additional level of the domain name. This is often referred to as the TLD+1.
- When determining whether a request is same-site or not, the URL scheme is also taken into consideration.
This means that a link from http://app.example.com to https://app.example.com is treated as cross-sites.
You may come across the term "effective top-level domain" (eTLD). This is just a way of accounting for the reserved multipart suffixes that are treated as top-level domains in practice, such as .co.uk.
- The difference between a site and an origin is their
scope; a site encompasses multiple domain names, whereas an origin only includes one.
Same Origin:
> Both URLs share the same protocol (HTTPS), domain (example.com), and port (443, implied by HTTPS).
https://example.com/page1
https://example.com/page2
Different Origin:
> The protocols are different (HTTPS vs. HTTP).
https://example.com/page
http://example.com/page
> The domains are different (example.com vs. sub.example.com).
https://example.com/page
https://sub.example.com/page
> The ports are different (443 vs. 8443).
https://example.com:443/page
https://example.com:8443/page