Basically everything shown - D is the diameter of the drilling tool - Aa is the milling depth and ar how much of the Material is removed.

For each Milling tool there are a List  where u need this information to use the tool the right way - right speed and right force.

D= diameter of the tool

aa = depth of cut or axial depth

ar = width of cut or radial depth

Best regards.

hi i know what it mean but i need program  drawing the fig above 

Solid works. But is difficult to use. I attach an image similar that you need!!!!

for the drawing you can use Corel Designer - this is relatively easy to use and had any tool you need therefore.

The shown Fig indicates :-

Tool rotating in Clockwise direction.

D is the diameter of the tool .

da is the depth of cut (depends on tool type ex:- diameter, coated or non coated, RPM of tool

dr is the width of cut (ideal width is 80% of tool diameter)