Teratoma is the most common type of ovarian germ cell tumor. The majority of these tumors are mature cystic tumors, while a minority are immature solid ones. Mature teratomas are also known as dermoid cysts, are mostly benign, and can occur at any age, mostly between 20-40 years old, often presenting unilaterally. Immature teratomas are malignant tumors, more commonly found in younger patients, and these tumors are usually solid and bilateral. The primary treatment method is surgical, with post-surgery pathology determining the benign or malignant nature of the tumor and guiding subsequent treatment decisions.