Incident,inciting incident and key incident

What is character but the determination of incident? And what is incident but the illumination of character?" Incident define as "a specific event or occurrence that occurs in relation to something else.  A incident serves two important and necessary functions in the craft of story ­telling: (1), it sets the story in motion; and (2), it grabs the attention of the reader and audience. Seeing the relationship between this first incident and the story line is essential to an understanding of good screenwriting

The inciting incident, was a cinematic tool he used to set up the story from page one, word one. The opening  incident, is called the inciting incident, because it sets the story in mo­tion; it is the first visual representation of the key incident, what the story is about, and draws the main character into the story line

Distinguish  an inciting incident and key incident

An  inciting incident that opens the film. It sets the story in motion. That is its function.the inciting incident will either be action-driven or character-driven. It does not have to be a tense action or dramatic sequence—it can be a scene involving a situation. In kuttam kadithal  the inciting incident is the boy student Chezhian response about a kiss , and the key incident comes when the the student fainted on the   teacher slap. 

In kaka muttai the children wish to get a piza for eat. they plan to get the  piza and lead many incidents. The kids are get ride from the shop that they wore dirty dress that is a key incident the put forward the story. 

The inciting incident always leads us to the key incident; which is the hub of the story line, the engine that powers the story forward. 
The key incident reveals to us what the story is about. 

These two incidents are essential parts of the whole that must be established when you are setting up the screenplay. Many times the key incident and Plot Point I are the same. Sometimes the key incident will be something that has affected  character's life at an earlier time.

The dramatic premise could be said to be a conceptual description of what the story is about, while the key incident would be that specific scene or se­quence that is the dramatic visualization of what the story is about.