Will the laptop with Wi-Fi 802.11Ac connect to the 802.11n standard network?

I want to buy a laptop, it says it works on 802.11ac. Will it work with my old router? I mean in general will the internet even if it’s on a/b/g/n standard?

Answer:

You can safely buy a laptop. It will work with your Wi-Fi network on the standard 802.11n, which is distributed by your router. And if you put in a dual-band router, you can connect your laptop to 5 GHz Wi-Fi (802.11ac) and get more wireless speeds.

This is the same as smartphones and tablets. All newer devices support 802.11ac, and have no problem working in the older n standard.