Also known as the “PHY” rate, this number captures the speed at which all data bits pass over the Wi-Fi network. Many Wi-Fi devices will report this number as the “speed” at which your network is performing. Actual throughout rates will always be lower than the data rate, due to available network capacity and overhead in real-world environments. The data rate communicates the maximum possible rate at which a device can transmit data. See also Throughput, which is a real-world measure of performance and is always lower than data rate.