The difference is that meditation is the very essence of Buddhism, not just the practice of a rarified elite of mystics. It’s fair to say that Buddhism is the most contemplative of the world’s major religions, which is a reflection of its basic nontheism.
Buddhism is about realization and experience, not institutions or divine authority. This makes it especially suited to those who consider themselves spiritual but not religious."
Melvin McLeod. "Are You Spiritual But Not Religious? 10 Reasons Why Buddhism Will Enrich Your Path." Shambhala Sun, October 2014 edition