What is the main programming language used on the internet?

with single programming language we cannot do anything on the internet. Actually every application in java is divided into three layers. Presentation layer, Application layer, Data layer. Every layer has its own specification. Presentation layer role is to interact with client means presentation layer takes input from the user and send it to Application layer. Application layer is a business logic layer. All the logic is done in this layer. Data layer contains the data.

for example:- suppose user enters student no. and student name in presentation layer, from here the data is send to application layer. In application layer we can write the logic for inserting, deleting, retriving and modifying the user data in database. From here the controller goes to datalayer to fetch data from database and sends the data back to user then the user see the corresponding data in the presentation layer.

For presentation layer: html, jsp, velocity etc are used.

For application layer: ejb, hibernate.......

for data layer: oracle.......