Viewership ratings are numerical values that indicate how many people are watching a particular television program or channel at a given time. These ratings help networks and advertisers understand the popularity of shows and make decisions about programming and advertising strategies. Higher ratings often lead to increased advertising revenue for networks. Ratings are typically measured by organizations like Nielsen, which uses various methods to collect data from a sample of households. This data is then extrapolated to estimate the total audience for a show. Viewership ratings can influence the renewal or cancellation of programs based on their performance.