Meditation originated in the East many thousands of years ago (via Positive Psychology). It traveled West a few hundred years ago but only became mainstream in the last few decades. Of course, the practice has changed over the centuries, and the contemporary practice probably looks much different than it did in previous centuries. But the goal is the same: to cultivate greater focus and awareness, to clear the mind of extraneous thoughts and worry, and to bring about greater peace of mind.
Meditation involves both mental and physical practices. Most often, it involves sitting still and quietly. But it can also include movement and even sound. There's not just one way to meditate. Meditation can look a lot like prayer, and you might wonder if it has religious associations. In some but not all cultures, it does. For some people, it's a spiritual practice, and for others, it's neither religious nor spiritual. The truth is, meditation is lots of things for lots of different people. You can make your meditation your own and adjust it to suit your personality and lifestyle.
Meditation also isn't just a practice you do for a limited period of time every day. You are meant to take pieces of it and practice them in your daily life, whether you're at work, talking to your mother, or in line at the grocery store behind that person who needs to price-check everything. That's an especially good time to practice.