Answer:
The TCP Protocol!
Step-by-step explanation:
The TCP (Transmission Control Protocol) is responsible for dividing files into chunks, adding headers containing information for reassembling packets in their original order, and verifying that the data was not corrupted while in transit (a process called error checking). A good way to put it is a 3 way handshake. You send a request, the client receives the request, the client delivers your request. Pretty neat!