New to CNC, couple questions left after searching

There is an older post on this forum named “Favorite Bits”. Here is my post on my favorite collets and bits to date:

The very inexpensive 1/8" carbide end mills ($14 for 10) and ball mills ($8 for 10) have been amazingly good workhorses. The bit diameters are dead on, and I’ve only broken a few of the end mills when I started working aluminum.