1. Linuxis a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive Unix systems. Linux has a reputation as a very efficient and fast-performing system. LINUX

2. 1) pwd-Print Working Directory.Shows the current location in the directory tree. 2) cd -Change Directory. When typed all by itself, it returns you to your homedirectory. 3) cd directory -Change into the specified directory name. 4) ls -List all files in the current directory, in column format. 5) clear -Clear the terminal screen 6) touch -Create empty file of zero byte 7) rm -Delete a file. 8) which -Shows the full path of shell commands found in our path 9) locate -A quick way to search for files anywhere on the filesystem. 10) ps -Lists currently running process (programs). LINUX COMMANDS 3. 11) w -Show who is logged on and what they are doing. 12) id- Print your user-id and group id's 13) df- Report filesystem disk space usage. 14) echo -Display text on the screen. 15) date -date to set your server's date and time 16) finger -Use finger to see who's on the system 17) cal -displays a calendar