Cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to the cognition process or different areas of cognition. Cognition, also known as cognitive function, refers to the mental processes of how a person gains knowledge, uses existing knowledge, and understands things that are happening around them using their thoughts and senses. A cognitive impairment can be in different domains or aspects of a person's cognitive function including memory, attention span, planning, reasoning, decision-making, language , executive functioning, and visuospatial functioning. The term cognitive impairment covers many different diseases and conditions and may also be symptom or manifestation of a different underlying condition. Examples include impairments in overall intelligence ,specific and restricted impairments in cognitive abilities , neuropsychological impairments , or it may describe drug-induced impairment in cognition and memory . Cognitive impairments may be short-term, progressive or permanent.