Typically you have main and guest to isolate them
You also have different networks for different bands because they use different radios (2.4GH and 5GH) with both having tradeoffs of range and speed.
Some have triband as well so that you can isolate high performance devices because every device on a network increases latency slightly, and more so a radio only support one broadcast method at a time and will downgrade its self to the least common dominator for the devices connected to it.