Complex sentence: The main difference between Jawi and Pegon is the later almost always written with vocal signs, due to Javanese language contains more variations of "aksara swara" (vowel symbols) than their Malay counterpart, so vocal sign needs to be written to avoid phonetic confusion.
Split into simpler sentences: The main difference between Jawi and Pegon is the latter almost always written with vocal signs. This is because the Javanese language contains more variations of "aksara swara" (vowel symbols) than their Malay counterpart resulting in vocal sign needing to be written to avoid phonetic confusion.