How website hosting works

The journey of a request

1. 1

   The browser resolves the domain

   It asks DNS which server holds the site, using the nameservers set at your registrar.

2. 2

   The server receives the request

   A web server such as Nginx decides whether the page is a file, a cached copy or something the application must build.

3. 3

   The application runs

   For WordPress or Laravel this means PHP executing and querying a database — the slowest step in most setups.

4. 4

   The response is encrypted and returned

   The SSL certificate encrypts the response; the browser renders HTML, then fetches CSS, JavaScript and images.

Domain, DNS and hosting are separate

Where the money goes

• Compute and storage — the resources your site is allowed to use
• Bandwidth — the traffic served
• Backups and retention — how far back you can restore
• Certificates and security — SSL, firewalls, patching
• Support — how quickly a person answers when something breaks

Migrating without downtime

1. 1

   Copy first

   Move the files and database to the new host and test on a temporary address.

2. 2

   Lower the TTL

   Reduce DNS time-to-live a day beforehand so the switch propagates quickly.

3. 3

   Switch DNS

   Point the records at the new server; keep the old one online while caches expire.

4. 4

   Verify then decommission

   Check forms, email and SSL before cancelling the old plan.