AC Router is a router supports IEEE 802.11ac wireless networking standard. The “AC” is from 802.11ac. IEEE 802.11 is a set of protocols, which includes 802.11 a/b/g/n/ac… etc.
AC routers provides much faster Wi-Fi speed than old a/b/g/N routers. AC router normally named by “AC + speed number”, like AC 1900. However, we should not be confused by the number 1900, it does not mean the AC 1900 router supports 1900 Mb speed.
Please check the following information on the photo:
AC router supports dual bands: 2.4 GHz and 5 GHz. From the print information, we know AC1900 means the router supports 600 Mb at 2.4GHz and 1300 Mb at 5Ghz. 1900 =600 + 1300. The highest WiFi speed of AC 1900 router is actually 1300 Mb.