SaaS stands for Software as a Service. It is an alternative way of accessing software from the traditional method of software purchasing. Previously, companies and individuals only had the option to purchase a standalone software package. This meant paying upfront a substantial amount for the license, and being responsible for hosting, installing and maintaining the software yourself. With SaaS, we setup, host, and maintain the service and you pay a flat setup fee and monthly service fee.
Simplicity and saving are only two advantages. Hosting the service on servers that are available 24/7 means your app is always available from anywhere in the world. And all your users automatically have access as well.