Third-party includes
A third party is typically a company that provides an auxiliary product not supplied by the primary manufacturer/webdeveloper. Countless third-party add-on and plug-in products keep the computer industry advancing at a rapid pace. These includes are generally provided by companies such as Facebook, Twitter, or Google, to allow you to access their functionality via a scripting language (mostly JavaScript) and use it on your website. One of the most obvious examples is using mapping-APIs (API: Application Programming Interface) to display custom maps on your pages.
But with every functionality that comes from outside of your domain, there's a certain risk attached; most bigger companies offer well-coded applications, but other third-parties could be less careful about their coding-practises and using their includes can bring severe security-risks with it. Next to that: linking to an outside source is itself a way for hackers to find vulnerabilities in the connection and while the API might be secure, the communication between the servers might be vulnerable to attacks.
