Is wanting to do something = desire?

Is wanting to do something = desire ? Doesn't enlightened people want to do anything ? They just react to whatever comes ? ( "react" may not be a suitable word). A related question that I hope to ask in Buddhism SE: How a enlightened monk differs from a enlightened lay person ? As I know: 1. Monks have intention to teach dhamma to others. 2. Monks can live more than 7 days. The first one have some relation to this question.