There are more than 2000 characters in ancient Egyptian writing. The characters stood for the sound of an object or an idea related to it. Hieroglyphs were usually used only for consonant sounds, not vowels. Vowels were part of their spoken language, but not in their written language.
Without vowels, several words could look the same but have completely different meanings. In order to clarify what a word was, context clues from the rest of the writings were used or a silent hieroglyph called a determinative. A determinative was added at the end of a word to give the reader a clue about the meaning. There were thousands of determinatives, which made learning to read and write hieroglyphics a very difficult job.
Hieroglyphs could be written from left to right or from right to left. The direction that the figures faced determined which way it should be read. If they faced left, the writing went from left to right; if they faced right, it went right to left.