I'raab is a grammatical concept in the Arabic language that refers to the system of case endings on words. It indicates the role of a word in a sentence, such as whether it is a subject, object, or possessive. The changes in the endings help convey meaning and clarify relationships between words. In Arabic, I'raab is essential for understanding the syntax of sentences. It involves different forms, such as nominative, accusative, and genitive, which are marked by specific vowel sounds or diacritics. Mastering I'raab is crucial for anyone learning Arabic, as it enhances comprehension and communication.