The way a computer uses a host of software to reach goals, brain uses a host of biologically driven software to dynamically reach goals of survival and reproduction by performing functions that make up what we call mind. As a matter of fact, software is the only entity that is suitable to be used as an analogy for mind.
In the way software affects hardware, e.g. the software command "eject" is responsible for a CD drive to eject, or "shutdown" command is responsible for a computer to shut down, it classifies mind as being responsible for actions generated by processes in matter, unlike the approach of dualism, which originated in the religion of Zoroastrianism more than 3000 years ago. According to dualism, there are two types of substances in the universe, physical substance and non-physical substance, and that mind is non-physical and is separate from body, which is physical (i.e. substance dualism), as popularized by René Descartes in 17th century. Dualism exists amongst a large population even today.
The main reason for such dualistic approach was that mind and body were not thought to be one emerging from the other, like the effects of software emerging from hardware, which was because there was no known concept of computers or information processing back then, which gradually came into existence in the last few decades and has now become a part of our day-to-day lives.
It has lasted till today because, even with computers, or for that "matter", information processing systems being common, there is nothing that explains that even if mind is taken for granted to be some biologically driven software, how such software would work to produce results offered by the phenomenon of mind is not known, especially in being capable of making its own decisions, and so, maybe it is something else. What adds up to it is the subjective experience mind offers, which cannot be seen, or should I say "felt", in computers and other information processing systems.