Mer means light, Ka means spirit, Ba means body.
In fact the Merkaba is the structure of spinning light which allows for the incarnation of the light body
It is a most accurate representations humanity has of Divine energy.
It is the infinite circulating flow of the divine trinity.
The Merkaba is a spinning structure of light similar to the chakras. The difference is that Merkaba is much larger, encompassing the entire body. In short we can say, we are inside the merkaba
It is actually symbolic of a great energy field surrounding our body beyond our auric field