The 2005 definition and classification of cerebral palsy (CP) aim to provide a comprehensive and updated framework for understanding and managing this neurodevelopmental disorder. The definition emphasizes that CP is a group of disorders affecting movement and posture, caused by non-progressive disturbances in the developing fetal or infant brain. These disorders often involve motor impairments, which may be accompanied by disturbances in sensation, cognition, communication, perception, and/or behavior, as well as seizure disorders. The classification system aims to categorize individuals with CP into groups based on the nature and typology of motor disorders, functional motor abilities, associated impairments, anatomic and radiological findings, and causation and timing. The classification includes four major dimensions: motor abnormalities, associated impairments, anatomic and radiological findings, and causation and timing. Motor abnormalities are categorized based on the type of abnormal resting muscle tone or involuntary movement disorder, such as spasticity, dystonia, choreoathetosis, or ataxia. Functional motor abilities are assessed using scales like the Gross Motor Function Classification System (GMFCS) and the Bimanual Fine Motor Function (BFMF) Scale. Associated impairments include conditions such as seizures, hearing or vision impairments, cognitive deficits, and emotional or behavioral issues. Anatomic and radiological findings involve describing the parts of the body affected and neuroanatomic findings from imaging studies. Causation and timing consider the identified cause and the presumed time frame of the injury. The classification system is designed to be multidimensional and to accommodate the variability in CP presentations. It aims to improve communication among clinicians, researchers, and health officials by providing a common language and framework for understanding and managing CP. The revised definition and classification reflect advances in the understanding of developmental neurobiology and the need for a more inclusive and accurate description of CP that accounts for the diverse range of impairments and functional limitations associated with the condition.The 2005 definition and classification of cerebral palsy (CP) aim to provide a comprehensive and updated framework for understanding and managing this neurodevelopmental disorder. The definition emphasizes that CP is a group of disorders affecting movement and posture, caused by non-progressive disturbances in the developing fetal or infant brain. These disorders often involve motor impairments, which may be accompanied by disturbances in sensation, cognition, communication, perception, and/or behavior, as well as seizure disorders. The classification system aims to categorize individuals with CP into groups based on the nature and typology of motor disorders, functional motor abilities, associated impairments, anatomic and radiological findings, and causation and timing. The classification includes four major dimensions: motor abnormalities, associated impairments, anatomic and radiological findings, and causation and timing. Motor abnormalities are categorized based on the type of abnormal resting muscle tone or involuntary movement disorder, such as spasticity, dystonia, choreoathetosis, or ataxia. Functional motor abilities are assessed using scales like the Gross Motor Function Classification System (GMFCS) and the Bimanual Fine Motor Function (BFMF) Scale. Associated impairments include conditions such as seizures, hearing or vision impairments, cognitive deficits, and emotional or behavioral issues. Anatomic and radiological findings involve describing the parts of the body affected and neuroanatomic findings from imaging studies. Causation and timing consider the identified cause and the presumed time frame of the injury. The classification system is designed to be multidimensional and to accommodate the variability in CP presentations. It aims to improve communication among clinicians, researchers, and health officials by providing a common language and framework for understanding and managing CP. The revised definition and classification reflect advances in the understanding of developmental neurobiology and the need for a more inclusive and accurate description of CP that accounts for the diverse range of impairments and functional limitations associated with the condition.