In plain words
Vidyā is what makes known man's true nature
The principle lies beyond the sights the senses deal with. Man is a triad of body, Manas and Ātma. Man has three natures: 1) the low animal nature 2) the human nature that knows the world 3) his true human nature. That is, the most important, the divine nature. This divine nature is man's true Ātma. It is man's true nature that is called ‘Vidyā’.