What is the main characteristic of Software-as-a-Service (SaaS)?

The main characteristic of Software-as-a-Service (SaaS) is that it offers software to subscribers on-demand over the Internet. This model allows users to access applications hosted in the cloud, meaning that they do not need to install or manage the software on their local devices. Instead, the software is maintained and updated by the service provider, simplifying the user experience and reducing the need for individual users or organizations to handle complex installation, maintenance, or infrastructure requirements.

In the context of modern technology, SaaS is highly beneficial for scalability and accessibility, as it allows users to access software from virtually anywhere with an internet connection. This is particularly advantageous for businesses that require flexibility and collaborative tools.

Other options highlight characteristics that are not inherent to SaaS. For instance, the need for hardware installation or local software installation would contradict the flexibility and cloud-based nature that SaaS provides. Physical network services are focused on hardware-centric solutions rather than software delivery, which further distinguishes SaaS as a model centered around internet-based access to applications.