A palindrome is a word, phrase, number, or sequence that reads the same backward as forward. Common examples include the words racecar and level. Phrases can also be palindromic, such as "A man, a plan, a canal, Panama!" which ignores spaces and punctuation. Palindromes can be found in various languages and are often used in puzzles and word games. They are not only fun to create but also serve as interesting examples of symmetry in language. Some numbers, like 121 or 12321, are also palindromic, showcasing this unique property in mathematics.