Matching text with Special meta-characters using Regular Expressions
Regex are more powerful and we want to do more than simply search for literal pieces of text. There are certain reserved meta-characters with Special uses and meaning. These "metacharacters" are: the square bracket [...], the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, the round bracket (…) and the Curly Brace {…}.