Definition - What does IEEE 802.11g mean?
IEEE 802.11g is an amendment to the 802.11 standard for wireless LANs. It is of of the specifications that is more commonly known as Wi-Fi.
802.11g has a theoretical throughput of 54 Mbps. It is the successor to the popular 802.11b specification, which has a maximum throughput of 11 Mbps. Both use the 2.4 GHz band, but 802.11g uses OFDM. 802.11g is backwards compatible and supports both 802.11b and 802.11g clients.
Techopedia explains IEEE 802.11g
802.11g, along with amendments a, b, d, e, h, i, and j, were rolled into what is now known as 802.11-2007, the current standard. A newer flavor is 802.11n, though it's common to see wireless routers with tri-mode capabilities. That is, the will provide for both 802.11n and 802.11b/g.