Below are the different reular expressions flavors
(1)Text Patterns and Matches
(2)Literal Characters
(3)Character Classes or Character Sets
(4)Shorthand Character Classes
(5)Non-Printable Characters
(6)The Dot Matches (Almost) Any Character
(7)Anchors
(8)ALTERNATION
(9)Repetition
(10)Greedy and Lazy Repetition
(11)GROUPING and CAPTURING
(12)Backreferences
(13)Named Groups and Backreferences
(14)Unicode Properties
(15)Lookaround
(16)Free-Spacing Syntax