You can distinguish the direction in which the text is to be read because the human or animal figures always face towards the beginning of the line. Also the upper symbols are read before lower. Alphabetic signs represent a single sound. Unfortunately the Egyptians took most vowels for granted and did not represent them. So we may never know how the words were formed.
Syllabic signs represent a combination of two or three consonants.
Word-signs are pictures of objects used as the words for those objects. A determinative is a picture of an object which helps the reader.