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, customer relationship management (CRM), and project management. This model allows for automatic updates and scalability, enabling businesses to easily adjust their usage based on changing needs without the hassle of traditional software management.