Jedi Initiate (or Youngling or "Jedi Hopeful") – a Force-sensitive child. Often a prospective Jedi was detected through blood sampling—those with great Force potential had high midi-chlorian counts in their bloodstream. At a very young age, children were removed from their families and assigned to the Jedi Temple for training. Younglings were taught in communal groups known as clans. At some points in history, this stage of training was also called the Jedi Apprentice stage. This was particularly true during the ancient wars when Jedi often started training older beings, and "Youngling" wouldn't fit. The older use of this term should not be confused with the Padawan stage.
Jedi Padawan – an apprentice who began serious tutelage under a single Jedi Knight or Jedi Master. In order to graduate to Padawan status, an Initiate was required to be chosen by a Knight or Master and taken as their sole pupil. If a youngling was not chosen to be a Padawan by 13 years of age, the youngling was placed into another, lesser role in the Jedi Service Corps, or they could choose to leave the Order. Depending on where the student's talents lay, this might be the Agricultural Corps, the Medical Corps, or the Exploration Corps. Padawans who were of a haired species typically wore a long braid of hair behind their right ear. When a Padawan was elevated to Knighthood, the braid was cut during the knighting ceremony. At least a few Jedi, though, were elevated to Knighthood simply by being told that they had passed whatever trials were considered necessary—most notably Obi-Wan Kenobi, and Vergere. Some exceptions of late acceptances to Padawan training were made, most notably in the case of Anakin Skywalker. In the days of the old Order, an Initiate could become a Padawan by passing less formal trials (understanding the Code, building a lightsaber, and facing a trial of the dark side itself)[1].
Jedi Knight – a disciplined Padawan could become a fully trained Jedi once they completed "the trials." The known trials were, but weren't limited to: the Trial of Flesh, the Trial of Courage, the Trial of Skill and the Trial of Self (also known as "facing the mirror").
A Padawan and a Master.
Jedi Master – a Jedi Knight who showed great understanding of the Force and managed to instruct a Padawan and train them successfully to the level of a Jedi Knight. This title could also be achieved through the performance of extraordinary deeds, or retaking the trials. Self-proclamation of the Jedi Master title was rare and frowned upon by the Jedi Council
Councilor (or Council Member) – A very few Jedi were invited to serve on the Jedi Council, the governing body of the Order. The Council was made up exclusively of wise, experienced Masters. The only Jedi Knight to sit on the High Council, Anakin Skywalker, was appointed by Supreme Chancellor Palpatine, although he was not granted the rank of Master simply because of this. Ki-Adi-Mundi served as a Councilor while undergoing the process of becoming a Master at the time of his invitation before Anakin, the Chosen One. The Council was made up of 12 masters, five of them holding life terms (two of them designated as "senior"), four holding long-terms, and three holding short-terms.
Master of the Order – The title used to denote the leader of the Jedi High Council. This title was held by Mace Windu until the beginning of the Clone Wars in 22 BBY, when he gave the title to Yoda.[2]
Grand Master – The highest rank of the Jedi Order was that of Grand Master. Yoda was once the Grand Master, as was Luke Skywalker following the Swarm War.