Music charts are rankings that show the popularity of songs and albums over a specific period. They are typically based on sales, streaming data, and radio airplay. The most well-known chart in the United States is the Billboard Hot 100, which ranks the top songs each week. Charts help listeners discover new music and track trends in the industry. Different countries have their own charts, such as the UK Singles Chart in the United Kingdom. These rankings can influence an artist's success and are often used to measure the impact of a song or album in the music market.