Regular Expressions, often abbreviated as regex, are powerful tools used in computer programming and text processing to search for specific patterns within strings of text. They allow users to define complex search criteria using a combination of characters and symbols. For example, a regex can be used to find email addresses, phone numbers, or any other structured data within a larger body of text. By using regex, programmers can efficiently validate input, extract information, or replace text. This makes them invaluable in tasks like data cleaning, web scraping, and form validation. Learning the basics of regex can greatly enhance one's ability to manipulate and analyze text data effectively.