the meaning of the output from iwlist scan

Question

i have a question to the output of iwlist scan. for instance i have the following result. There are multiple entries with IE. What does the IE stand for? Becasue there are multiple entries i guess there are different encryption options for this Wifi. What are all options can be displayed there? "WPA Version 1","IEEE 802.11i/WPA2 Version 1","unkonw" what is about WEP? Or EAP? How this will be displayed?

      Cell 01 - Address: 00:1F:F3:02:04:81
                ESSID:"Apple Network"
                Mode:Master
                Channel:1
                Frequency:2.412 GHz (Channel 1)
                Quality=42/100  Signal level:-84 dBm  Noise level=-127 dBm
                Encryption key:on
                IE: WPA Version 1
                    Group Cipher : TKIP
                    Pairwise Ciphers (1) : TKIP
                    Authentication Suites (1) : PSK
                IE: IEEE 802.11i/WPA2 Version 1
                    Group Cipher : TKIP
                    Pairwise Ciphers (2) : CCMP TKIP
                    Authentication Suites (1) : PSK
                IE: Unknown: 2D1A2C0217FFFF000000000000000000000000000000000000000000

Answer 1

IE : Information Elements

Refer to Management Frames,

Management frames are quite flexible. Most of the data contained in the frame body uses fixed-length fields called fixed fields and variable-length fields called information elements. Information elements are blobs of data of varying size. Each data blob is tagged with a type number and a size, and it is understood that an information element of a certain type has its data field interpreted in a certain way. New information elements can be defined by newer revisions to the 802.11 specification;

IEEE 802.11i-2004 is standard that specifies security mechanisms for wireless networks.

Wi-Fi Protected Access (WPA) is security protocol and security certification program.

sorry I can't find iwlist result with WEP and EAP.....

How about use iw command? The n mode on “iwlist wlan0 scan”