Two kinds of desire

"The Buddha spoke of two kinds of desire: desire that arises from ignorance and delusion, which is called tanha, craving, and desire that arises from wisdom and intelligence, which is called kusala-chanda, or dhamma-chanda, or most simply chanda. Chanda has a range of meanings, but in this case I’m using it to mean wise and intelligent desire and motivation, which the Buddha stressed as being absolutely fundamental to any progress on the eightfold path.

In the presence of chanda, effort, or viriya, arises. Effort is in many ways the characteristic dhamma of this whole school of buddhism. In fact, the Buddha referred to his teachings not as Theravada but as viriya-vada. It is a teaching of effort, a teaching that there is such a thing as effort, that effort can be put forth, effort should be put forth, and that effort is what is needed for progress on the path."
~ Ajahn Jayasaro