Your skin's natural oils are often stripped during the bathing process, whether from hot water or harsh products. Glycerin which is a sweet, viscous by-product of soap making, and can help lock in your skin's natural moisture and prevent over-drying. This may be especially beneficial if you experience drying conditions like: acne.
Commercial soap producers remove glycerin, hence the reason commercial bars don't 'sweat' and are often very irritating and drying for our skin (the plethora of chemical fillers dont help either 🤔
Glycerine soap is also hypoallergenic, so can confidently be used on babies delicate skin too.
The bar pictured below is pure organic glycerin with chamomile from my garden.  These bars are available with or without chamomile.  Chamomile free bars are rectangular.