PHP is a server-side scripting language used to create dynamic web pages. It is used on 65.45% of top websites and allows you to collect form data, add/modify database data, and restrict page access. JavaScript is a client-side scripting language embedded in web browsers that is used for functions like autocomplete, layout fixes, and enhancing HTML. AngularJS is an open-source JavaScript framework for building dynamic web apps using HTML. Node.js is an environment for building server-side applications, primarily used for network programs like web servers. SQL is a database server that allows you to execute queries, retrieve data, and manage databases.