Remote File Inclusion (RFI) is a type of vulnerability most often found on websites. It allows an attacker to include a remote file, usually through a script on the web server. His pair, Local File Inclusion or LFI is basically the same technique, used on sites which have been successfully penetrated, and the hacker "planted" his files already on the server.
You might heard lot of weird expressions and acronyms when is coming about hacking. What XSS, LFI and all these things are meaning? You can find'em here!
A website is stored within a file system on a server. Some of the server's file system is therefore exposed to the outside world and can be accessed by an end-user's web browser. The part of the file system (or directory structure) that is visible to the outside world is limited to a specific root folder and its contents.
HTTP stands for 'HyperText Transfer Protocol', and it is the mechanism used to transfer data from one computer to another across the Internet. You can use HTTP to request information from a server, or to send information to a client by wrapping the request or data in a 'packet'.
There are numerous other tactics that can be used to break into a computer system, and these usually involve discovering weaknesses or loopholes in the server software's defenses. When a programmer writes software that runs on a web server, he tries to make sure that the software cannot be abused - but it can be very difficult to foresee every eventuality; vandals and hackers are always pushing software to the limit and trying out operations which the software was not designed to handle, in an attempt to discover a way in.