Like everything else in Hinduism, meditation is an individual's take which cannot be generalized. Some people will say that keeping everything out of thinking is meditation. That opens the person's eyes to some ultimate truth. Some believe that contemplation on one particular subject is the aim of meditation. I belong to the second set. Some will do it with exercises, other will be happy just to sit and contemplate. Some believe that meditation will give them supernatural powers, others think that is all hogwash.
Yoga swamis Sivananda and Vishnudevananda (the second being the disciple of the first), for example, instruct several types of meditation for different purposes.
But are you asking about the goal of meditation or about the means?
I'm not familiar with Buddhist approach, but as others have said, the entire idea of meditation, the words itself, and what it means, varies a ton. Each school will describe how they meditate in a different way.
I will hazard a guess for the OP: Not much. Hindus and Buddhists interacted undisturbed for more than a millennium. There was much give and take in philosophy and process of meditation. They may be using different terms for the same process.