A "people meter" is a device used to measure television viewing habits in households. It records which programs are being watched and for how long, providing valuable data to television networks and advertisers. This information helps them understand audience preferences and tailor their content accordingly. Typically installed in a sample of homes, people meters track the viewing behavior of all household members. Each person is assigned a unique code, allowing the device to differentiate who is watching what. This data is then aggregated to represent broader viewing trends across different demographics, aiding in programming and advertising decisions.