Software-as-a-Service (SaaS) is a cloud-based software delivery model where applications are hosted on the internet and accessed via a web browser. Users do not need to install or maintain the software on their local devices, making it convenient and cost-effective. Instead, they typically pay a subscription fee to use the service. SaaS applications cover a wide range of functions, including email services, customer relationship management (CRM), and project management tools. This model allows for easy updates and scalability, as users can access the latest features without needing to manage installations or upgrades themselves.