Software delivery models refer to the various methods used to distribute and deploy software applications to users. Common models include on-premises, where software is installed locally on a user's hardware, and cloud-based, which allows access via the internet without local installation. Each model has its own advantages and challenges, influencing factors like cost, maintenance, and accessibility. Another popular model is Software as a Service (SaaS), where applications are hosted by a provider and accessed through a subscription. This model simplifies updates and scalability for users. Understanding these models helps organizations choose the best approach for their specific needs and resources.