Epistolary refers to a literary genre that uses letters, diary entries, or other forms of correspondence to tell a story. This format allows readers to gain insight into characters' thoughts and emotions through their personal writings. It can create a sense of intimacy and immediacy, drawing readers into the characters' experiences. Many famous works are epistolary, such as Mary Shelley's "Frankenstein" and Alice Walker's "The Color Purple." These narratives often explore themes of communication, isolation, and personal growth, making the epistolary form a powerful tool for storytelling.