One of the main differences between WiFi and Broadband is how they would allow you to connect to the internet. When you are connected using WiFi, this is wireless. You do not need to have a cable in order to connect to the internet.
When you are using broadband, you need to connect your gadget to the modem with the use of the broadband cable. Between the two, broadband will offer a more stable connection. This explains why people who are working on big projects or would need to be constantly connected to the internet may choose to be connected through broadband as compared to WiFi.
Yet, being connected to WiFi is considered to be more convenient.