Inside of each person is a garden. When we are young this garden is ripe with the seeds of character, and through our lives some of these seeds grow and bloom. Some bloom into gorgeous flowers while others bloom into invasive weeds. Each of us, on our journey of life, make choices that decide whether we water our flowers or water our weeds, whether we pull out our flowers or pull out our weeds.
Our characters are no different. Each of them has a life in which they encounter a slew of choices, whose decisions dictate the state of the garden inside their hearts. This is character growth, or character arc.
In a story, whether it be a novel or a short story, something always changes in the gardens of one of more of the characters, and not just in the main character. These changes affect the way the characters view their past, present, and future. The character at the beginning of the story and at the end of the story do not make the same decisions if faced with the same choices. If they do, then your character has not grown.
This doesn’t mean that your character changes. Change and growth are not actually the same thing…despite the immediate thought that when your character grows, they change. The person that they become has always been there – their seeds have just been hidden until this moment.
For instance, I am not the same person as I was five years ago. I’ve had experiences and have made decisions all along the way. However, I am still me. I have not changed into someone else. The person I am right now has always been there carefully nurtured by the choices I have made. I have learned and I have grown. I have not intrinsically changed.
Keep this in mind when you are writing your characters. They will always be who they are right now, but they need to grow. We all need to grow.