Introduction to CURL?

What is PHP/CURL?

CURL is the name of the project. The name is a play on 'Client for URLs',
originally with URL spelled in uppercase to make it obvious it deals with
URLs. The module for PHP that makes it possible for PHP programs to access curl-
functions from within PHP.

We can use several web protocols using one uniform interface (CURL), most notably FTP, FTPS, HTTP, HTTPS, GOPHER, TELNET, and LDAP.

In March of 2001, the Curl Corporation launched the Curl Language, their Run
Time Environment (RTE), and their Integrated Development Environment (IDE).

A very powerful feature of the Curl Language is its Just-In-Time compiling.
Curl code is sent over the Web as source code. Curl’s compiler, which ships as part
of the runtime environment, sits on the client computer and compiles the source
code directly to the client’s low-level code. The goal is to minimize the load on the
servers and to capitalize on the end-user’s machine’s processing capability, rather
than their relatively slow communication rate.

TIP: If you are using fopen and fread to read HTTP or FTP or Remote Files, and experiencing some performance
issues such as stalling, slowing down and otherwise, then it's time you learned a thing called cURL.

Performance Comparison:

10 per minute for fopen/fread for 100 HTTP files
2000 per minute for cURL for 2000 HTTP files

cURL should be used for opening HTTP and FTP files, it is EXTREMELY reliable, even when it comes to performance.

Reference sites :

1. What is cURL, libcurl, PHP/CURL?
2. PHP/CURL Examples Collection