Final answer:
Applications and system software allow users to carry out tasks at the highest level of abstraction. The complexities of programming and hardware are made transparent to the user. Software developers usually work in the tertiary sector of the economy.
Step-by-step explanation:
The applications and system software allow users to carry out tasks on a computer at the highest level of abstraction. This is because, at this level, users interact with the computer through user-friendly interfaces without needing to understand or manage the underlying code or hardware. For example, when using a word processor or a web browser, the complexities of the programming and electronic operations are abstracted away, enabling users to focus on their tasks like document editing or internet browsing.
As for the sector of an economy where a software developer would typically work, it is the tertiary sector, which focuses on providing services rather than producing goods. The tertiary sector encompasses a wide range of services, including information technology services, which is where software development usually falls. There's also a quaternary sector, known for knowledge-based services such as research and development, but software development is most commonly associated with the tertiary sector.