What exactly is data, how is it made? and why does it cost 'data' to use the internet?

Data is the amount of packets in bytes you have used through the internet itself. Data (packets), has been around since the start of the internet; its bytes of information sent through the web (simple term). Also, the main reason it costs to use it is simply because, the companies that have access to transport these packets through their servers (very costly) needs to have the money a month to keep their hosting service for the packets open!