A block of PHP code that has a name and it has a property that it is reusable it can be executed from as many different points in a PHP Program as required. Also known as a method (if it is inside a class). Most Joomla code is inside functions/methods.

Adjusting a core Joomla file (i.e., the files that you uploaded before installing Joomla!). Any changes you make to core files will be overwritten during the next update, thus core hack is not recommended. In most cases, there are alternative workaround to change Joomla without hacking the core.

RSS (which stands for, among other things, Really Simple Syndication) that allows you to syndicate your site content. It defines an easy way to share and view headlines and content through newsfeeds. You can find RSS feeds in hundreds of thousands of places on the Internet which allow you to stream their articles into RSS readers - or your Joomla site.

The Feed Display module allows you to display other sites’ RSS feeds on your site, which is a great way to keep your content from being static.