A buffer is a temporary storage area in computer memory that holds data while it is being transferred between two devices or processes. This helps manage differences in speed between the sender and receiver, ensuring smooth data flow. Buffers are commonly used in applications like video streaming and file downloads, where data needs to be processed in chunks. In networking, a buffer can also refer to a space in a router or switch that stores incoming data packets before they are forwarded. This prevents data loss during high traffic periods and helps maintain efficient communication between devices, such as computers and servers.