Mental capacity refers to an individual's ability to make decisions and understand the consequences of those decisions. It involves cognitive functions such as reasoning, understanding, and the ability to communicate choices. Mental capacity can vary from person to person and can be affected by various factors, including age, mental health conditions, and cognitive impairments. Assessing mental capacity is important in legal and healthcare settings, as it determines whether a person can make informed choices about their own life. In many cases, individuals with diminished mental capacity may require support from family members, caregivers, or legal representatives to ensure their best interests are upheld.