The proverb "birds of a feather, flock together" is connected with the idea that people who have certain characteristics in common are always together.
The literal meaning of this proverb is: "birds who share the same feather color, fly together".
The word "flock" is used to refer to a large group of animals or people who share a specific characteristic. When we see birds flying together, we can see that they share more than one feature, such as color and breed.
