Automagically is a slang term used to describe processes that are too complex to be explained easily. Automagically is frequently used to describe computers and other technology that function in a way that is diffult for non-experts to grasp. The term automagically is usually employed when the speaker feels a full explanation is not worth the effort it would take to be understood.
Although the term predates it, Arthur C. Clarke’s third law stating, “Any sufficiently advanced technology is indistinguishable from magic,” nicely sums up the concept of automagically. Technology, and computing technology in particular, has reached a point where it is difficult for the layperson to grasp how the underlying processes produce outward results. Therefore, it has become easier to think of things happening automagically, rather than spending the time and effort to figure it out.