The Padawan braid was a braid traditionally worn by a Jedi apprentice, to symbolise their status as a learner.
The braid was worn on the right side, beginning above the ear and braided behind it to hang down towards the shoulder. When a Padawan reached a certain point in their training, or passed a certain test, a coloured tie would be added to signify the progress of their apprenticeship. It is unknown how many tests/colours there were for a Padawan to acquire; In The Phantom Menace, Obi-Wan Kenobi has red and yellow ties in his braid, and in Attack of the Clones Anakin Skywalker has blue and red ties in his.
A Padawan braid would continue to grow until the Padawan in question passed his or her knighthood trials, at which point the braid would be cut off with a lightsaber during the knighthood ceremony.
Some hairless species took to forming Padawan braids out of silka beads or similar materials. Ahsoka Tano (a Togruta from the Clone Wars series) wears one such silka bead “braid”.
In the New Jedi Order, the order established by Luke Skywalker after the fall of The Empire, the tradition of Padawan braids was all but forgotten due to the fact that most knowledge of the old order had been wiped out. Ben Skywalker did however wear one at one point.
Whether or not the fact that the braid was the symbol of a Padawan learner was a well known fact amongst “civilians” is unknown; In Attack of the Clones Queen Jamillia of the Naboo addressed Anakin Skywalker as “Master Jedi”, even though his braid was highly visible. This may however just have been out of respect of his status as a Jedi, as many outside the order commonly referred to any Jedi as “Master”, despite their rank within the order.
Within real world history, braids have had many different meanings in various cultures. For example, a Native American belief states that the three strands of a braid represent the past, present and future, and braiding them together makes one one with one’s ancestors and descendants.