what are the benefit of meditation?

Meditation practice will train mind to focus on specific objects, like: breath or body sensation, which will relief brain from high dense thoughts or strong emotions. It can help brain calm down and be present in current situation. It will avoid the mind to get lost in past regrets or get too anxious in the future desire. This is not only help brain to get great rest, but also an efficient exercise for brain to rebuild the neuron cells and extend their connections.
Reports showed, even 15 mins daily meditation can greatly help people with mitigating nervous, pressure, sadness and almost all negative emotions. 
Long time mediation can lead mind in the "deep calm down" state, which can help people understanding things in the deep root and see things as they really are. These will be the foundation to trigger wisdom and enlightenment. 
Just like human boy need work out, human brain also need exercise, which is meditation. Meditation now becomes more and more popular and lots of people already get benefit from it and keep it as a daily exercise.