Software as a Service (SaaS) is a cloud computing model in which a third-party provider delivers software over the internet on a subscription basis. SaaS applications are accessed through a web browser, and the provider is responsible for hosting, maintenance, and updates.

SaaS is one of the three main categories of cloud computing services, along with Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). It is the most high-level and fully-managed form of cloud computing, providing users with access to software applications without the need to install or maintain them locally.

One of the main benefits of SaaS is its ease of use. SaaS applications are typically accessed through a web browser, and users do not need to install or maintain any software locally. This makes it easy for users to get started with SaaS applications and reduces the burden of IT management.

SaaS also offers a number of cost benefits compared to traditional on-premises software. It allows users to pay only for the software they use, rather than having to make upfront investments in licenses and hardware. It also provides a high degree of scalability, allowing users to easily increase or decrease their usage as needed.