Which characteristic is essential for application software?

The essential characteristic for application software is operating system compatibility. This is crucial because application software is designed to run on top of an operating system, which serves as the platform that manages hardware resources and provides services for running applications. If an application is not compatible with the operating system, users will be unable to install or execute the software on their devices, rendering it ineffective.

While inherent security features, sales tracking capabilities, and low-power consumption are valuable aspects of certain applications, they are not universally essential for all types of application software. Security features are important but depend on the application’s purpose and the data it handles. Similarly, sales tracking capabilities are specific to business applications, and low-power consumption is more relevant for mobile applications and devices rather than a characteristic of application software as a whole. Therefore, the fundamental requirement of operating system compatibility underlines the ability of application software to function properly in a user's computing environment.