Well, on an remote off chance that we are not speaking of toolmakers buttons...
From the top:
#1 - takes a photo and opens the dialog where you can set it as a reference image for the display
#2 - opens a photo for the same purpose.
User manual page for it is here:
TouchDRO Reference Image Overlay. This post:
Reference Image Function in TouchDRO Plus has some more info.
#3 - turns on automatic sub-datum selection (i.e. as you move towards a coordiante, it will be automatically selected)
#4 - same for guide lines (user manual here:
Working with TouchDRO Guide Lines)
#5 - turns on automatic tool offset direction changes (when #4 is turned on). (same user manual page as above)
#6 - turns on automatic proximity/"near-zero" warning (same user manual page as above)
#7 - auto-selection of sub-datum on spindle down/up movement
#8 - automatic creating on sub-datum on spindle down/up movement (useful when you need to perform multiple operations, i.e. spot drill, drill, countersink, tap. On the first operation the DRO will add the coordinate, then turn on #3, and just move between the saved sub-datums.
Hope this helps
Yuriy