SMB2, or Server Message Block version 2, is a network communication protocol used for sharing files, printers, and other resources over a network. It was introduced by Microsoft in 2006 as part of the Windows operating system, enhancing the performance and security of file sharing compared to its predecessor, SMB1. This protocol allows multiple clients to access shared resources simultaneously and supports features like improved caching, larger file sizes, and better error handling. SMB2 is widely used in local area networks (LANs) and is essential for enabling seamless communication between devices in a Windows environment.