ELI5: Explain Like I'm 5

Non-synchronous transmission

Non-synchronous transmission is when two computers exchange information without making sure the information arrives at the same time. This means that some messages can be sent very fast and others can take longer. Think of it like sending a postcard in the mail. It might take a few days for the postcard to get delivered, but it will get there eventually. Non-synchronous transmission is the same thing but it happens with computers instead of postcards.