SaaS, which stands for Software as a Service, is a way of delivering software over the internet. Instead of buying and installing software on individual computers, users access it through a web browser, usually on a subscription basis. With SaaS, the software provider hosts and maintains the application, taking care of updates, security, and infrastructure, while users simply pay for access and use the software as needed. This model offers flexibility, scalability, and cost-effectiveness for businesses and individuals.