This document provides an introduction to Unix/Linux operating systems. It discusses that Unix was developed in the 1960s and is the predecessor to Linux. It then covers connecting to Unix/Linux systems, the shell interface, navigating the file system using commands like ls, cd, pwd. It also summarizes key commands for working with files like cp, mv, rm and editing files. Finally, it touches on permissions, running programs, input/output redirection and accessing remote systems using ssh/scp.