What is a BIOS file?
BIOS stands for “Basic Input Output System”.
Various electronic devices and computers have code stored in them that runs when you turn them on and while they operate.
What this means for game console emulators is that they need to essentially do the same thing that the real system’s BIOS does in order to play the games.
Many emulators do all of this by themselves, but some (especially for CD based systems) require a copy of the BIOS file to work.
The Seedi instructions will tell you what the files are, and how to copy them via Wi-Fi.