ASP.NET Zero is a Visual Studio solution. It's built based on a layered architecture and other software best practices. It includes pre-built pages, a solid, strong, scalable solution architecture, and much more.
ABP is a complete framework for building modern web applications by following software development conventions and best practices. A full-stack web application infrastructure and modern architecture; Domain Driven Design (DDD): Using DDD patterns and principles for the design and development of a web application.
ASP.NET Core is a high-performance, cross-platform, open source framework for building modern, cloud-enabled, Internet-connected applications. With ASP.NET Core, you can: Build web applications and services, Internet of Things (IoT) applications, and mobile backends.