Quoting

Escape Character	How to remove the special meaning from a single character.
Single Quotes	How to inhibit all interpretation of a sequence of characters.
Double Quotes	How to suppress most of the interpretation of a sequence of characters.
ANSI-C Quoting	How to expand ANSI-C sequences in quoted strings.
Locale Translation	How to translate strings into different languages.

Quoting is used to remove the special meaning of certain characters or words to the shell. Quoting can be used to disable special treatment for special characters, to prevent reserved words from being recognized as such, and to prevent parameter expansion.

Each of the shell metacharacters (see Definitions) has special meaning to the shell and must be quoted if it is to represent itself. When the command history expansion facilities are being used (see History Interaction), the history expansion character, usually ‘!’, must be quoted to prevent history expansion. See Bash History Facilities, for more details concerning history expansion.

There are three quoting mechanisms: the escape character, single quotes, and double quotes.