What does it mean to send a short composition?

"Writing a composition" usually refers to a short article or a letter written to a childhood friend and a friend for many years. This kind of composition is usually to express feelings such as missing, blessing and feeling about childhood, or to share one's life, experience and feelings. Writing a short composition is usually a way of emotional communication, which can deepen the feelings between friends and let them better understand each other's life and inner world. In the traditional culture of China, writing prose is also regarded as an important cultural tradition, which represents friendship and the preciousness of friendship.