Final answer:
A software developer works in the quaternary sector, which deals with ideas and information management. The tertiary sector, which provides services, is the largest sector in developed countries, making up the majority of the GDP.
Step-by-step explanation:
Someone working as a software developer would be in the quaternary sector of an economy. This sector is involved with the production of ideas, managing information, research, new technologies, and high levels of education and arts. By comparison, the primary sector involves the extraction and production of raw materials, the secondary sector processes those materials into finished goods, and the tertiary sector provides services such as healthcare, finance, and child care.
In developed countries like the United States, the tertiary sector makes up more than three-quarters of the economy. The largest sector, in terms of contribution to the gross domestic product (GDP), is therefore the tertiary sector. The tertiary and quaternary sectors together are often thought of as the service sector.