What type of software operates between the operating system and applications?

Middleware is a type of software that acts as a bridge between the operating system and the applications that run on top of it. Its primary function is to facilitate communication and data management for distributed applications. Middleware allows different software components, which may be developed in varying programming languages or run on different platforms, to interact seamlessly. It can manage tasks such as message passing, authentication, and data transformation, ensuring that the applications can exchange data and utilize shared resources efficiently.

In contrast, firmware refers to low-level software that is embedded in hardware devices to control their functions, which is different from the operational layer that middleware operates within. Malware is malicious software designed to harm, exploit, or otherwise negatively affect computers and networks, and it does not serve a legitimate purpose in the context of operation between the OS and applications. Drivers, while essential for enabling the operating system to communicate with hardware components like printers or graphics cards, do not provide the same level of service to facilitate inter-application communication as middleware does.