Software as a Service (SaaS) is a software distribution model in which a vendor hosts applications and makes them available to customers over the Internet. This model requires customers to pay a subscription fee on a periodical basis (monthly, quarterly, or annually) for the use of the application. SaaS applications are usually web-based and can be accessed from any device with an Internet connection, such as a laptop, tablet, or smartphone. These applications are hosted on remote servers owned and managed by the vendor, eliminating the need for customers to buy and maintain their own hardware. Additionally, SaaS offers scalability, reduced upfront costs, and access to the latest version of the application, as well as ongoing support and maintenance from the vendor. For these reasons, SaaS is becoming increasingly popular and is likely to remain so for the foreseeable future.