The "C Layer" refers to a specific level in the OSI model, which is a framework used to understand network communication. It is often associated with the transport layer, responsible for end-to-end communication and data transfer between devices. This layer ensures that data is sent and received accurately, managing error detection and correction. In the context of programming, the "C Layer" can also refer to code written in the C programming language. This language is widely used for system programming and developing applications due to its efficiency and control over system resources. The C Layer allows developers to interact closely with hardware and optimize performance.