Vowel harmony is a linguistic phenomenon where vowels within a word harmonize to share certain features, such as frontness or backness. This means that if a word starts with a front vowel, the other vowels in that word will also typically be front vowels. This concept is common in languages like Turkish and Finnish, where vowel harmony affects suffixes and word formation. In vowel harmony systems, vowels are often categorized into groups. For example, in Turkish, the front vowels include e and i, while the back vowels include a and o. This system helps maintain a consistent sound pattern, making pronunciation easier and more fluid for speakers.