The browser walks a fixed sequence of small steps before anything shows. First it parses the URL into scheme, host, and path. It resolves the hostname into an IP address. Then it opens a connection to that server on the right port.
Over that connection the browser sends an HTTP request for the path. The server replies with a status code and usually an HTML body. The browser parses the HTML and finds more resources: stylesheets, scripts, images. It fetches each one, often over the same connection.
Each step adds delay, so a slow page usually has one clear culprit. It might be DNS, connection setup, server time, or heavy assets. Knowing the sequence tells you where to look first.
This answer doesn't lend itself to a diagram - it reads best . No credits were charged.
Why there's no diagram: “”
The interactive diagram is below the answer - jump to diagram ↓ · Below it, the related concept . Jump to it ↓
The diagram below the answer is the concept . Jump to it ↓