Functional magnetic resonance imaging (fMRI) measures quick, tiny metabolic changes that take place in the brain, providing the most sensitive method currently available for identifying, investigating, and monitoring brain tumors, stroke, and chronic disorders of the nervous system like multiple sclerosis, and brain abnormalities related to dementia or seizures. This overview explores experimental research design, outlines challenges and limitations of fMRI, provides a detailed neuroanatomic atlas, and describes clinical applications of fMRI in cognitive, sensory, motor, and pharmacological cases, translating research into clinical application.