Why are some routers labeled as AC, while others are AX?
It all boils down to the WiFi standard that the router supports. Routers with AC in their name only support up to the WiFi 5 standard, while routers with AX in their name should support the latest WiFi 6 standard, which includes benefits such as increased speed, reduced congestion, and better battery life for your devices.
In a bit more detail: every few years, the Institute of Electrical and Electronics Engineers (IEEE) releases a new WiFi standard. The official terminology for WiFi standards is denoted by the number 802.11, followed by a combination of letters.
The latest generation is officially known as 802.11ax, or Wi-Fi 6. It's often shortened to AX.
This is in contrast to the last generation, which was known as 802.11ac and Wi-Fi 5. Its short-term name is AC.