Yoda is one of the main protagonists of the Star Wars franchise.
He is an extremely wise, experienced, skillful, and powerful yet eccentric Jedi. He was the most knowledgeable and trained Jedi Master and was the wisest, strongest, and most powerful Jedi of his time, immensely powerful with the use of the light side of the Force and exceptionally skilled in lightsaber combat with centuries worth of training, experience, and knowledge in.
For his surpassing wisdom, skill, and power, Yoda was the Grand Master of the Jedi Order who helped train Luke Skywalker and many other Jedi as well as facing off against and nearly defeating the most formidable of villains, such as Count Dooku and even Palpatine himself - he is a gentle teacher, but like all Jedi will fight fiercely to defend the galaxy from the dark side of the Force.