The shell prompt can vary. When you enter a command and it is running, the operating system does not display the shell prompt. When the command completes its action, the system displays the prompt again. This indicates that you can enter another command. The flag alters the way a command works.
Many commands have several flags.
A parameter consists of a string of characters that follows a command or a flag. It specifies data, such as the name of a file or directory, or values. The backslash is placed at the end of the first line. When certain commands are entered, the shell prompt changes. Any command that you issue within a program is known as a subcommand.