From the Document: "The 'cost of living' (COL) is an economic term referring to the amount of money people need to achieve a certain standard of living. It is largely determined by the prices of goods and services consumers must buy to reach that standard, including housing, food, energy (e.g., electricity and gas), medical care, and leisure, among many others. The federal government produces several measures of prices in the economy. For example, the Consumer Price Index and the Personal Consumption Expenditures Price Index track prices paid for goods and services by households."
CRS Report for Congress, R47037
Congressional Research Service: https://crsreports.congress.gov/