curl is a command line tool for transferring data with URL syntax
Curl is free and open software that compiles and runs under a wide variety of operating system
Php curl is basically used to fetch data from the web, the following code will fetch the yahoo.com home page
$url = "http://www.yahoo.com";
$ch = curl_init(); // Initialize a CURL session.
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // Return Page contents.
curl_setopt($ch, CURLOPT_URL, $url); // Pass URL as parameter.
$result = curl_exec($ch); // grab URL and pass it to the variable.
curl_close($ch); // close curl resource, and free up system resources.
echo $result; // Display page contents.
?>
Curl_init() : initialize a new session and return a CURL
