There are said to be four traditional meditation "postures":
Walking (not something we typically consider a posture, but for the sake of differentiation we do here)
We generally recommend sitting because it offers a nice balance of focus and relaxation. Feel free to lie down if you feel like you’re able to sustain your attention without falling asleep. Standing is a great posture to practice with as we spend a lot of our day in this posture, and meditating while standing (or walking) can help to develop mindfulness that will carry over into daily activities. The main idea is that when you do your formal meditation practice, you aren't also doing something else.