Minor character

There are many ways to add depth to a story and expand the range of possibilites and diversities within it.  One of these methods is adding minor characters. These characters may not play significant roles in the story, often appearing only once or twice, but their presence makes the narrative more realistic and complete. However, this is true only when they are well-writen. If the author handles them poorly, they can disrupt the story and create unnecessary distractions.
Paul Jenkins describes minor characters as "Minor characters can also be used to add depth and texture to a story. By filling out the world in which the story takes place, they can make it seem more real and believable. They can also help move the plot forward or provide information that’s important to the development of the story. " 

Basic principles of creating minor characters:

First, give them distinctive personalities of their own. Even though they appear only for a brief moment, make them unique. 

Second, estabilish a meaningful connection with the main characters. In just a few sentences, provide them with a purpose and reason for being in the story. 

Third, add an element of mystery to these minor characters. This will pique the reader's intrest and allow you to bring them back later with dropping hints about their hidden secrets.

Works cited: 

Paul Jenkins., "How to write minor characters", Brilliantio, 26. May 2022, https://brilliantio.com/how-to-write-minor-characters/