What allows files containing text, programs, graphics, numerical data and so on to be downloaded off or uploaded onto a network?

File Transfer Protocol

Explanation:

In computer networks and data communication, the client- server network architecture is very popular, in this network architecture, bigger computers designated as servers respond to clients request for information (This could be text, programs, graphics numerical data etc.) The File Transfer Protocol shortened as FTP is the standard network protocol that allows the transfer of these files between the clients and servers.

This protocol is build for the client server achitecture and it is the protocol by which files are shared between computers  on the internet.