Middleware is a software layer that facilitates communication and data management between different software applications or components, typically in a client-server architecture. It acts as an intermediary, allowing disparate systems to interact without needing direct connections. For instance, in real-time compositing software, middleware can simulate a camera by interfacing with the operating system and applications like Skype, effectively creating a virtual camera that modifies the input before it reaches the application. This concept extends to various scenarios, such as security filters that mediate between an email client and a server, enhancing functionality and control over data flow. Middleware is often considered a buzzword in tech discussions, emphasizing its role in enabling complex interactions in software systems.