What does 'curl' command do?

The curl command is a powerful and versatile command-line tool used for transferring data with URLs.

In this specific step, when you run curl http://localhost, it:

1. Makes an HTTP request: It acts like a web browser in a terminal, sending a request to the web server running on localhost (which means your own machine) on the default HTTP port (usually 80).
2. Retrieves the content: It fetches the content from the specified URL. In this case, it retrieves the index.html file that your Python web server is serving.
3. Prints the response: It then prints the retrieved content directly to your terminal. You should see the HTML content: <h1>Welcome to LabEx Firewall Demo</h1><p>This server is running on port 80</p>.

Essentially, curl allows you to interact with web servers and other network services directly from your command line.