The word seder is a Hebrew word meaning order. It refers to the ritual presentation of Passover, or more specifically the reading and acting out of the Haggadah. The typical seder consists of fourteen (sometimes fifteen) parts. Today these are done in identical order almost without exception. They are:
Note: The reciting of the Haggadah is not considered an official step of the Seder since the Seder is administered through the Haggadah and therefore runs throughout.
It is difficult to determine precisely when the Seder was first developed, although we do find the essence of it in the Mishnah (2nd Century c.e.). There is strong indication that the Seder was already solidly in place near the end of the Second Temple Period (516 b.c.e. 70 c.e.) and many believe that Jesus and his disciples performed a seder at the Last Supper. However, there is no doubt that at least one thing has changed in the Seder since that time. The Mishnah records that immediately following the Karpas - כרפס , the Shulchan Orech - שלחן ערך  was served, occupying the present location of the Yachatz יחץ. This would elicit the asking of the Four Questions that would lead to the Maggid -םגיד. However, it is later recorded in the Talmud that the Shulchan Orech - שלחן ערך is not served until well after the Maggid - םגיד. This altered order is still practiced today almost exclusively, probably in order to keep the attention of the celebrants, particularly the children, throughout.
It is also noteworthy to take notice of the similarities that exist between the Seder and the dinner of Greek and Roman antiquity. The Jews were heavily influenced by Greek and Roman culture during the Second Temple Period (516 b.c.e. 70 c.e.), and it is not unlikely that some aspects of this dinner of antiquity found their way into the order of the Seder.
This dinner began with wine and hors doeuvre, which were taken while seated in the antechamber. The diners then proceeded to the main course, which they ate while reclining on pillows as a sign of a free and affluent person. The meal typically consisted of bread with meat or fish, and as a rule was taken with wine. At the conclusion of the meal, a dessert of fruit or some other delicacy was eaten and grace was said. In most occasions, this was climaxed by enthusiastic drinking.
The order of the Seder loosely follows this same pattern. It begins with drinking wine the Kaddesh - קדש. This is followed by the Karpas כרפס, or hors doeuvres. In the Second Temple Period (516 b.c.e. 70 c.e.), the meat of the paschal sacrifice was the main dish and was served with unleavened bread and bitter herbs. Today, bread with meat and/or fish constitutes the main portion of the meal. After the meal, the Afikomen is eaten as dessert, and this is followed by at least two more cups of wine.
Lehmann, Rabbi Dr. Marcus of Mainz. Passover Haggadah (Jerusalem:
Feldheim, 1983) 5
 Zeitlin, Solomon. Jesus and the Last Supper.
Printed in The Passover Haggadah. ed. Nahum N. Glatzer (New York:
Schocken Books, 1979) xii
Glatzer, Nahum N. The Passover Haggadah (New York: Schocken Books,
 Glatzer ---