Let's say that the summon of meditation is enlightement or nirvana. It is supposed to be a good 'thing'. But is it good because there is no suffering any more, or did you get something instead of it that is good in itself?
Meditation involves mastery over the mind (concentration) and to know things as they are (wisdom).
When developing concentration the the Jhana Factors arise of which one is Joy. Also when wisdom increases the Enlightenment Factors develop out of which Joy is one. Meditation does induce Joy and in progress where one stage you encounter is Joy: Upanisa Sutta, (Ekā,dasaka) Cetanā’karaṇīya Sutta, (Dasaka) Cetanā’karaṇīya Sutta, etc.
Nirvana is the final goal. There is no Joy associated with it but is a good thing as there is no suffering but Joy is included in suffering as it is impermanent, can come to an end, pass away, fade away, cease, change as described in Raho,gata Sutta.
Both. Meditation when done properly will allow one to abandon the Five Hindrances (greed, anger, sloth/torpor, restlessness, doubt); and give rise to the Five Jhana Factors where each factor counters a particular hindrance:
- Applied Examination to counter sloth/torpor
- Sustained Examination to counter doubt
- Joy to counter anger
- Happiness to counter restlessness
- One-pointedness to counter greed.
It's important to notice that meditation alone will not lead one to nibbana. It's only 1 out of 8 limbs of the Noble Eightfold Path, which a practioner will need to train to perfection.