boolean

see boolean logic.
Something is boolean if it can only assume 2 values... ie 1 or 0, true or false. The concept of boolean mathematics was invented by a man named bool.

and you better like boolean math, cuz you use it everyday!

In 3D packages Booleans are the application of the principle of is, and is not, to the intersection of objects resulting in a new shape which is:

• Combined volume of positive objects.
• Positive objects minus what intersects with negative objects.
• Only the intersecting portion of the remainder of all positive objects with intersection objects.

This can often be applied in layers, or groups, where the result of a minus b is intersected with c, and then subtracted from d, and so on. This is also called Boolean Modeling.