Additional information:

Wifi Clients Modes (Lower Pane)
There are 3 different modes that you can view the wifi clients in the lower pane:
Show Clients Of Selected AP: In this mode, WifiChannelMonitor only displays the wifi clients that are connected to the access point you select in the upper pane.
Show All Clients: In this mode, WifiChannelMonitor displays all detected clients.
Show All Clients Without AP: In this mode, WifiChannelMonitor displays all clients that are not connected to any access point.
AP Columns Deion
SSID: The name of the wireless network
MAC Address: MAC address of the access point.
Company: Company that manufactured this access point, determined according to the MAC address.
PHY Type: 802.11g, 802.11n, and so on...
Frequency: Channel frequency in MHz.
Channel: Channel number.
RSSI: Specifies the signal strength, in dBm. Some drivers don't provide the correct RSSI values in monitor mode.
Security: None, WPA-PSK, WPA2-PSK, WPA-PSK + WPA2-PSK, WPA-EAP, WPA2-EAP, WPA-EAP + WPA2-EAP, or WEP.
Cipher: None, WEP, TKIP, CCMP, TKIP+CCMP.
Beacons: The total number of beacons sent by the access point. Beacon is a packet sent frequently by the access point and contains essential information that the wifi client need to identify and connect it.
Probe Responses: The total number of times that the access point responded to a probe request sent by a wifi client.
Data Bytes: Total number of data bytes sent and received by this access point.
Retransmitted Data: Total number of retransmitted data bytes sent and received by this access point.
Device Name: The name of the device. This value is displayed only for devices that support WPS.
Device Model: The device model. This value is displayed only for devices that support WPS.
WPS: Specifies the WPS status: No (No WPS Support), Configured, Not Configured, or Locked.
Start Time: Displays the last time that access point was possibly started/restarted/rebooted. Be aware that some access points reset their timestamp periodically without restart/reboot action, and thus for these APs, the time value displayed on this column doesn't represent the correct start time.
First Data Detected On: The first time that sent/received data was detected for this AP.
Last Data Detected On: The last time that sent/received data was detected for this AP.
Wifi Client Columns Deion
MAC Address: MAC address of the wifi client.
Company: Company that manufactured this wifi client, determined according to the MAC address. For example, if the wifi client is iPhone or iPad, you'll see 'Apple' in this column.
RSSI: Specifies the signal strength, in dBm. Some drivers don't provide the correct RSSI values in monitor mode.
SSID List: When wifi client tries to connect one or more access points, this field will display the list of network names (SSIDs) that this client tries to connect.
Sent Data Bytes: Total number of data bytes sent by the client.
Received Data Bytes: Total number of data bytes received by the client.
Retransmitted Sent: Total number of retransmitted data bytes sent by the client.
Retransmitted Received: Total number of retransmitted data bytes received by the client.
Client Type: Wifi Client, Router, or Unknown.
Wifi Client means that this client uses wireless connection.
Router means that this client is the router (Yes... the router is also displayed as a client in the network).
Unknown means that this client uses wired connection or wireless connection.
Device Name: The name of the device. This value is displayed only for devices that support WPS.
Device Model: The device model. This value is displayed only for devices that support WPS.
WPS: Specifies the WPS status: No (No WPS Support), Configured, Not Configured, or Locked.
PHY Type: 802.11g, 802.11n, and so on...
Security: None, WPA-PSK, WPA2-PSK, WPA-EAP, WPA2-EAP, or WEP. This field is filled only when the client tries to connect the access point.
Cipher: None, WEP, TKIP, CCMP, TKIP+CCMP. This field is filled only when the client tries to connect the access point.
Probe Requests: Total number of probe requests sent by this client.
First Detected On: The first date/time that this client was detected.
Last Detected On: The last date/time that this client was detected.
Meaning of Icons
Green Icon - The AP or wifi client sent or received data in the last 10 seconds. (You can change the number of seconds in the 'Advanced Options' window)
Orange Icon - The AP or wifi client sent or received data in the last 60 seconds. (You can change the number of seconds in the 'Advanced Options' window)
Red Icon - No sent/received data in the last 60 seconds.
Google Translation:
Wi-Fi Client Modes (bottom panel)
There are 3 different modes that can be viewed by Wi-Fi clients in the bottom panel:
Show Clients of selected APS: In this mode, WifiChannelMonitor displays only WiFi clients connected to the access point selected in the top panel.
Show All Clients: In this mode, WifiChannelMonitor displays all detected clients.
Show all clients without an access point: In this mode, WifiChannelMonitor displays all clients that are not connected to any access point.
AP Columns Description
SSID: Wireless network name
MAC Address: The MAC address of the access point.
Company: The company that is manufactured by this access point is determined according to the MAC address.
PHY Type: 802.11g, 802.11n, and so on...
Frequency: Channel frequency in MHz.
Channel: Channel number.
TOOTS: Determines the signal level, in dBm. Some drivers do not provide the correct RSSI values in monitoring mode.
Security: No, WPA-PSK, WPA2-PSK, WPA-PSK + WPA2-PSK, WPA-EAP, WPA2-EAP, WPA-EAP + WPA2-EAP or WEP.
Cipher: No, WEP, TKIP, CCMP, TKIP + CCMP.
Beacons: The total number of beacons transmitted by the access point. A beacon is a packet sent frequently by an access point and contains the necessary information that a WiFi client needs to identify and connect it.
Probe Responses: The total number of times that the access point has responded to the probe request sent by the WiFi client.
Data byte: The total number of bytes of data sent and received by this access point.
Retransmitted data: The total number of bytes of retransmitted data sent and received by this access point.
Device Name: device name. This value is displayed only for devices that support WPS.
Device Model: Device model. This value is displayed only for devices that support WPS.
WPS: Determines the WPS status: No (No WPS support), Configured, Not configured, or Closed.
Start Time: Displays the last time that the access point was possibly started/rebooted/rebooted. Be aware that some access points periodically reset their timestamp without restarting/restarting actions, and thus for these access points, the time value displayed on this column does not represent the correct startup time.
First Data detected on: The first time the transmitted/received data was detected for this AP.
Last data detected on: The last time the transmitted/received data was detected for this AP.
Wi-Fi Column Client Description
MAC address: The MAC address of the WiFi client.
Company: The company that produced this Wi-Fi client is determined according to the MAC address. For example, if the WiFi client is an iPhone or iPad, you will see Apple in this column.
TOOTS: Determines the signal level, in dBm. Some drivers do not provide the correct RSSI values in monitoring mode.
SSID List: When a WiFi client tries to connect one or more access points, this field will display a list of network names (SSIDs) that this client is trying to connect to.
Data bytes sent: The total number of bytes of data transmitted by the client.
Received data bytes: The total number of data bytes received by the client.
Retransmitted Sent: The total number of bytes of retransmitted data transmitted by the client.
Retransmitted to the editor: The total number of retransmitted bytes of data received by the client.
Client Type: WiFi client, router or residence.
The client's Wi-Fi means that this client is using a wireless connection.
Router means that this client is a router (Yes. .. the router is also displayed as a client on the network).
Unknown means that this client is using a wired connection or a wireless connection.
Device Name: device name. This value is displayed only for devices that support WPS.
Device Model: Device model. This value is displayed only for devices that support WPS.
WPS: Determines the WPS status: No (No WPS support), Configured, Not configured, or Closed.
PHY Type: 802.11g, 802.11n, and so on...
Security: No, WPA-PSK, WPA2-PSK, WPA-EAP, WPA2-EAP or WEP. This field is filled in only when the client tries to connect to the access point.