Weighting refers to a process in which data is adjusted or modified based on certain criteria, such as demographics, to better represent a population. In statistics and survey research, weighting is used to compensate for differences in the sample that may not be fully represented by the sample design. This can include factors like age, gender, race, education level, income, etc., which could affect responses or participation rates. By applying weights based on these characteristics, the data becomes more accurate and representative of the population as a whole.