Progressive apps are web apps that have native app-like features and functionality, such as offline capabilities, push notifications, and access to device hardware. They are accessed through a web browser and can be installed on the home screen like a native app, but they do not need to be downloaded and take up minimal space on the device. Native apps are built specifically for a certain platform, like iOS or Android, and are downloaded from app stores. They have greater access to device functionality and can offer a more seamless user experience but require more development time and maintenance.