This document discusses enterprise applications, including what defines an enterprise application, how they can be categorized, and the challenges they face. Enterprise applications are applications that satisfy an organization's business and functional requirements while also considering efficiency, scalability, security, and other non-functional needs. They can be categorized based on their visibility to end users, the industry domain, type of processing, and whether they are custom-built or readymade. Developing successful enterprise applications requires business case readiness, a clear strategy for execution, and excellence in implementation. It also discusses the key skills needed and how to measure the success of enterprise applications.