Have you ever heard the saying "birds of a feather flock together"? This means that people who have similar interests or personalities tend to hang out or "flock" together. The same idea can be applied to computers and technology.
In computing, "birds of a feather" refers to groups of people who have similar interests in a particular area of technology. For example, there might be a group of people who are all interested in artificial intelligence. They might share information with each other, attend the same conferences, and generally help each other out.
These groups of people are important because they help advance technology in a particular area. By working together and sharing ideas, they can come up with new and innovative solutions to problems. They can also share their knowledge with others who are interested in the same area.
So, to put it simply, "birds of a feather" in computing refers to people who share a common interest in a particular area of technology, and who work together to advance that technology.