Answer:
For most of ancient Egyptian history there were only two scripts: hieroglyphic text, used for monumental inscriptions, tombs, statues, buildings and so on - and hieratic, which is a cursive form of the same hieroglyphs used for keeping records, writing letters and in mathematical, legal and medicinal texts. Hieratic derived directly from hieroglyphs and seems to have existed right from the beginning; it was usually written in black ink and always from right to left.
Very late in Egyptian history, around 650 BC, a third script was introduced. This was Demotic, which is a much simplified and mutated form of hieratic. Demotic texts do not reflect the hieroglyphic equivalent sign for sign, as hieratic does.
Demotic is from the Greek word meaning "of the people", but it essentially replaced hieratic for writing documents and letters and it does not mean that more ordinary people became literate. It is full of ligatures, abbreviations and peculiar language constructions which make it very difficult to read and almost impossible to transcribe into hieroglyphs - it appears to have been influenced by classical Greek and Roman scripts.
Coptic borrowed six letters from Demotic for its writing system.