Can I put new soil on top of old soil?

I'm curious about gardening practices and I've heard conflicting opinions on whether or not it's advisable to add new soil directly on top of old soil. Can you explain the potential benefits and drawbacks of this approach? Is it a viable option for improving soil quality and promoting plant growth, or could it potentially harm the plants or the soil structure in the long run? I'd appreciate any insights you can provide on this topic.