In economics, "sectors" refer to different parts of the economy that group similar businesses and activities. The main sectors include the primary sector, which involves natural resources like agriculture and mining; the secondary sector, which focuses on manufacturing and construction; and the tertiary sector, which provides services such as healthcare and education. Each sector plays a vital role in the overall economy. Understanding sectors helps us analyze how economies grow and change. For example, as a country develops, it often shifts from the primary sector to the secondary sector and then to the tertiary sector. This transition can lead to more jobs and improved living standards for people.