Silicone lubricant is a very popular type of personal lubricant. It's popularty comes down to the quality and properties of the silicone base. Typically speaking, silicone lubricant is thicker, more viscous, and much longer-lasting than water based lube. The feel of silicone lubricant is completely different than that of water-based lube.
Once it is on, you usually won’t need to reapply it so it is perfect for longer play sessions or just a very smooth and silky play session. In most cases, silicone lubricants have very few ingredients beyond just liquid silicone.
Occasionally they will also include an aloe extract or vitamin E for added moisturizing to the skin but that’s about it. Due to this small ingredient list, silicone lube is actually an ideal lubricant for those that tend to experience irritation from other lubricant types. Silicone lube has fewer additives than water based lubes so it is much less likely to irritate or cause a reaction.
This is because silicone lubricant is not absorbed into the skin or mucous membranes like water based lube is. Silicone has much larger molecules and these glide over the skin as they are too large to be absorbed. This is why it is so long-lasting. It will remain on the skin until you decide to remove it.