Swar Sandhi refers to the phonetic rules in the Hindi language that govern how sounds combine at the junction of words. It plays a crucial role in pronunciation and meaning, as the way two words connect can change their sounds and, consequently, their interpretations. There are two main types of Swar Sandhi: Swar Sandhi involving vowels and Swar Sandhi involving consonants. In vowel combinations, the sounds may merge or change to create a smoother transition between words. Understanding these rules is essential for proper communication and fluency in Hindi.