Early writing systems like Egyptian hieroglyphics and Sumerian cuneiform used pictographs or ideographs to represent words and ideas. The Phoenician alphabet originated around 1500 BC and was one of the first to use letters to represent consonant sounds. The Greek alphabet expanded on this to represent each sound with a single letter, helping form the foundation of the Roman alphabet which added letters and became the most widely used writing system globally. Spelling can be phonetic, semantic, or etymological based on representing sounds, shared meanings, or original word origins respectively.