The Four Categories of Character
The characters within a story exist to communicate thematic intent to an Audience. While incomplete themselves, they complete a story by collaborating in a collective transmission of the Storyform.
Characters fall into four categories, as per their relationship to the Storyform:
Fundamental Characters supply the thematic argument's main perspectives and include the Main Character Throughline perspective and the Influence Character Throughline perspective. The former offers a first-person personal point-of-view, while the latter supplies an objectified individual point-of-view. Both are essential components fundamental to the purpose of a story.
Primary Characters and Secondary Characters communicate the Objective Story Throughline perspective. The difference lies in their composition. Primary Characters consist of several Objective Character Elements, coalescing on occasion into observable Archetypes like Protagonist or Antagonist. Secondary Characters offer the same objective Elements but in a limited and individualistic capacity. Primary over Secondary refers to the number of Elements; the more Elements a character possesses in a story, the more critical—and primary—they feel to a story.
Tertiary Characters are those you could remove and see no significant impact on the story's meaning. Characters must contain at least one Objective Element to be perceived as relevant. Storyform is everything. If the character lacks a tie to the Storyform, the character is disposable.
A story is not a storyform. Characters exist to communicate a message and to provide colorful illustrations of storytelling. This virtual chaos on the edge of meaning eschews the pop and crackle aesthetic of static that warms a radio broadcast. The message gets through, but invitingly and similarly to "real life."
Avoid sacrificing your imagination to the cold-hearted master of narrative structure. Recognize the throwaway status of those lacking apparent connection to a Storyform, but maintain your artistic integrity.
You don't win a prize for writing an excellent story structure.