A regular expression is a pattern of text that allows the pattern to be matched against a string of text. They can also be used for more complex tasks such as finding and replacing strings of text or parsing HTML.
Regular expressions are a programming language that is used to match patterns in text. They are often used in search engines and text processing programs, but they can also be used for other purposes such as finding URLs or email addresses.
Regular expressions are powerful tools that allow us to perform complex searches across large amounts of text. They have many uses in programming languages, operating systems, and in other computer-related tasks.