Ancient Egyptians used pictures to make a phonetic alphabet as in a rebus, so that each sound could be written with a picture-word, a "phonogram" or "pictograph". For example, a zig-zag for water n came to mean the letter "n", because the Egyptian word for water started with n. This same picture became our letter 'M' in the Latin alphabet, because the Semitic word for water started with m, and Semitic workers changed the symbols to fit sounds in their own language. In the same way, our Latin letter 'N' came from the hieroglyph for snake D as the word for "snake" started with n in Semitic. In Egyptian, this picture had stood for a sound like English "J" because of their word for snake. Some pictures came to represent ideas, and these are known as "ideograms".