A brain tumor refers to the abnormal growth of cells within the brain tissue. These growths can originate from various sources, including the brain's own cells, or from cells that have traveled to the brain from another location in the body. Tumors are classified by their origin and behavior, ranging from benign growths that are typically localized and slow-growing, to malignant tumors that invade surrounding healthy tissue. Diagnosis usually involves neuroimaging techniques and often requires tissue sampling for definitive pathological classification. Treatment approaches are highly varied and depend on the tumor's type, location, and degree of invasiveness, commonly involving surgical intervention, radiation therapy, or systemic medication to manage growth and control spread.