There are many postures available to you for meditation.
If you are new to meditation, you may wish to try a variety of postures in order to find a few that best meet the needs of your body and your mind.
If you are experienced in one or a few postures, you may wish to try something different.

Sitting is probably the most common posture for meditation because,

• for most people,
• in most circumstances,
• it balances comfort and alertness well.

​You may choose to

• sit on the floor or
• on a chair.

(follow those links for more info)

Other options are:

• standing
• walking
• lying down
• kneeling

Other things to consider:  
What to do with your head
What to do with your hands