Before you can appreciate PHP/CURL, you'll need to familiarize yourself with PHP's built-in functions for downloading files from the Internet.
PHP includes two simple built-in functions for downloading files from a network—
fopen() function does two things. First, it creates a network socket, which represents the link between your webbot and the network resource you want to retrieve. Second, it implements the HTTP protocol, which defines how data is transferred. With those tasks completed,
fgets() leverages the networking ability of your computer's operating system to pull the file from the Internet.