Difference between mx, tx and xx in image name?

[Aleksandar Ilic]

I have Cisco AP 2702E and when I run dir command I get output below:

ap#dir
Directory of flash:/ap3g2-rcvk9w8-mx/

39 -rwx 215867   Jan 1 1970 00:16:08 +00:00 ap3g2-rcvk9w8-mx
40 -rwx 73           Jan 1 1970 00:16:08 +00:00 ap3g2-rcvk9w8-tx
41 -rwx 5935032 Jan 1 1970 00:18:10 +00:00 ap3g2-rcvk9w8-xx

Show version is givin me:
System image file is "flash:/ap3g2-rcvk9w8-mx/ap3g2-rcvk9w8-xx"

And show boot:
BOOT path-list: flash:/ap3g2-rcvk9w8-mx/ap3g2-rcvk9w8-mx

What is the difference between images with those different letters in the end???

[Milos Megis]

I think that mx means that image is after start extracted into RAM memory and it is running there.

I don´t know anything about other types.