Let’s start with a simple client-server setup. A single server runs everything including web app, caching, database, etc.

1. When a client enters a URL(such as www.google.com) in the Web browser, it contacts the DNS (Domain Name System that acts like a phonebook mapping domain names to IP addresses) to find the correct IP address of the web server.
2. The HTTP request is then sent to the web server using the IP address obtained from the DNS.
3. The web server returns its response in HTML or JSON format back to the client.