SMB 1.0, or Server Message Block version 1.0, is a network protocol used for sharing files, printers, and other resources on a local area network. Developed in the 1980s, it allows applications to read and write to files and request services from server programs. This protocol enables communication between computers running different operating systems, primarily in Microsoft Windows environments. However, due to security vulnerabilities, SMB 1.0 is considered outdated and has been largely replaced by newer versions, such as SMB 2.0 and SMB 3.0, which offer improved performance and security features.