Software as a Service (SaaS) is a cloud-based service where applications are hosted by a third-party provider and made available to users over the internet. This model allows businesses to access software without the need for installation or maintenance, reducing costs and increasing efficiency. SaaS applications are typically subscription-based, enabling users to pay only for what they use. Popular examples include Salesforce, Google Workspace, and Microsoft 365, which provide essential tools for collaboration, customer relationship management, and productivity, all accessible from any device with internet connectivity.