The document discusses Software as a Service (SaaS) and compares it to traditional on-premise software. It covers perspectives of both SaaS vendors and customers. For vendors, it discusses the paradigm shift required in application architecture, business models, and marketing strategies. It also discusses operational considerations like infrastructure, billing, support and data security. For customers, it evaluates criteria like collaboration needs, cost of ownership, upgrade requirements, functionality needs, and speed of implementation to determine if SaaS is suitable over traditional software.