How data transfer through Internet?

no one knows

Geez, well that's useful...here's the real answer:

Data transmission is the physical trasfer of data over a point-to-point or point-to-multipoint transmission medium. The data is often represented as an electro-magnetic signal, such as an electrical voltage signal, a radiowave or microwave signal or an infra-red signal. So in other Words, the 'package' (the data that is being sent) is delivered to their destination and put together to form the whole thing, because the package was split up in different parts.