What does the x means in 802.1x and which are the differences between the 802.1X and 802.11 standards ? Can you explain to me ?
802.1X is a standard for port-based network access control (NAC). It belongs to the IEEE 802.1 family, defining (mostly) data link layer standards (bridging).
802.11 is a standard for wireless networks with various physical layer variants, often called Wi-Fi or wireless LAN / WLAN.
802.11 commonly uses 802.1X for client authentication, but apart from that they are completely different things.
There are quite a few IEEE 802 standards around.