Actionscript is the object-oriented programming language used to create flash software. Thre current version, AS3, allows more control and executes much faster than the previous.
Flash is a multimedia platform used to add interactive and animated content to web pages. Although usage may be declining, new technolgies haven't yet proven as efficient, so it still maintains popularity, specially in web games, advertisement, audio and video streaming.
PHP is a server-side programming language that gives the possibility to create dynamic content to websites and access databases. It is so extensively used, it's probable static pages will soon be absolete, if they're not already.
Wordpress is a Content Management System for websites and is probably the most popular blogging system nowadays. It includes a template feature allowing customized development. It is based on PHP and makes estensive use of jQuery.