What Programming language used for the web?

Several languages are used. The initial version of the World Wide Web defined HTML. Since then several "back-end" languages have been defined that run on servers; PHP and ASPX are the most common with varieties of Visual Basic and Visual C# being used alongside ASPX. Javascript is also used to run small applications on the browser and SQL is used to interact with databases. Most modern websites use a mixture of several of these languages.