Software as a Service (SaaS) is a software distribution model that delivers applications over the internet, allowing users to access and use software without needing to install it on their devices. SaaS applications are hosted on cloud servers and are typically subscription-based, providing users with regular updates and support. Popular examples include Google Workspace, Salesforce, and Microsoft 365. SaaS offers flexibility, scalability, and cost-effectiveness, making it an attractive option for businesses of all sizes.