How the trace works
The check starts at https://your-domain/ and follows Location headers for up to five hops, recording the status code and destination of each. If HTTPS does not answer at all, it starts from plain HTTP instead and says so. Redirects that point at private or internal addresses are not followed.
Only HTTP redirects are traced. A redirect done with JavaScript or a meta refresh tag happens inside the browser after the page has loaded, and does not appear here.
301, 302, 307, 308
301 and 308 are permanent: browsers cache them and search engines move their index entry to the new address. 302, 303 and 307 are temporary: the original URL stays the one that is indexed. 307 and 308 additionally guarantee that the request method is kept, which matters for forms and APIs.
When a site moves for good, from HTTP to HTTPS or from one domain to another, a single permanent redirect per URL is what you want. A temporary redirect left in place for years is one of the most common migration mistakes.
Chains and loops
Each hop costs a full round trip before anything is shown, and crawlers give up after a handful. http → https → www → /home is three hops that can usually be collapsed into one. A loop, where two URLs redirect to each other, ends in the browser error ERR_TOO_MANY_REDIRECTS; here it shows up as a chain that stops at the hop limit.