Traditional software (often called on-premise software) is purchased via a perpetual license and installed locally on a user's physical computer hardware or internal company servers, making the buyer responsible for manual updates, backups, and maintenance. In contrast, Software as a Service (SaaS) is a cloud-computing delivery model where applications are hosted remotely by a third-party provider and accessed securely over the internet via web browsers on a subscription basis, with the vendor managing all automatic updates, security patches, and server hosting.