When I send data from the arduino to the the computer via USB, what encoding does it use. For example, If i send 10 byte data, it gets converted to ASCII and I can read the ASCII data on the computer's end. However, I need to know what type of ASCII (i.e which code page)
The data is sent as eight bit bytes. There is no encoding / code page.
Show some code. You can do anything you like but if you can share some code, it will be clear. Plus, when unsure, turn on the arduino IDE's serial monitor and see.