boolean is a totally different thing in 3d software. It’s where you remove something from another something or combine.
Nah, it’s exactly the same thing. 3D software is just applying a Boolean function to two sets of points at the same time, instead of one scaler piece of data like reading a setting.
In other words, Firefox is doing f(a), where f is a unary Boolean function (identity or negation) and a is a single true/false value, while your 3D software is doing f(A, B), where f is a binary Boolean function (union a.k.a. AND, intersection a.k.a. OR, etc.) and A and B are vectors of true/false values representing whether particular points of space are contained within object A or B respectively.
(Some 3D software might be more sophisticated than that, using mathematical expressions of the object boundaries to get exact answers instead of interpolating between points, but I’m just trying to convey the basic concept here.)