What is "djoser"

Djoser (also read as Djeser and Zoser) was an ancient Egyptian pharaoh of the 3rd dynasty during the Old Kingdom and the founder of this epoch. He is well known under his Hellenized names Tosorthros (from Manetho) and Sesorthos (from Eusebius). He was the son of king Khasekhemwy and queen Nimaathap, but if he also was the direct throne successor is still unclear. Most Ramesside Kinglists name a king Nebka before him, but since there are still difficulties in connecting that name with contemporary horus names, some Egyptologists question the received throne sequence.