A changelog is a record of changes made to your product, typically organized by version or release. It allows customers to see what updates and improvements have been made, and how those changes may impact their use of the product.
Product managers have to tell customers how their product is distinctive from others. You can stand out from the crowd if you can do that well. It can be your way to get a competitive advantage in a market where more significant players dominate. This article describes which factors are relevant to SaaS companies with some examples.