Aloe Vera gel encourages skin repair and new skin cells.  The gel also contains a pail reliever called carboxypeptidase, which may be why it is soothing for sunburns.

Aloe Vera gel contains compounds that suppress inflammation by showing the enzymes that trigger it who's boss.

Because it is mostly water, it helps to hydrate the skin without that post application greasy feeling.  It helps lock moisture into the skin while also acting as a glue that makes the top layer of skin cells stick together ultimately smoothing and softening your skin.