Initially, the Korn shell is set up as the login shell. Although some commands can be entered by simply typing one word, other commands use flags and parameters. Each command has a syntax that designates the required and optional flags, files, and parameters. Flags modify the way the command runs. The operating system runs the commands sequentially.
Commands are case-sensitive.
The shell distinguishes between uppercase and lowercase letters. A backslash signifies line continuation to the shell. The following example is one command that spans two lines. When you enter a misspelled command, the shell may return an error message. You might get an error message even if it appears that you typed the command correctly.