This shows that you don't know what WiFi really is. It's a wireless Ethernet interface. It's a carrier or transmitter and receiver of other transport protocols, not an implementation of one. You cannot transmit a file using WiFi.
You have to use an application protocol, like FTP, HTTP, or even a protocol of your own design, transported via another protocol, like TCP/IP, to communicate with another device or computer. Look at what TCP/IP stands for: Transmission Control Protocol/Internet Protocol. It's a transport protocol, not an application protocol.