Unified Communications as a Service (UCaaS) is a delivery model in which a variety of communication and collaboration applications and services are outsourced to a third-party provider and delivered over an IP network, usually the public Internet.
UCaaS technologies include enterprise messaging and presence technology, online meetings, telephony and video conferencing. UCaaS is known for providing high levels of availability (HA) as well as flexibility and scalability for core business tasks.
Currently, there are two primary "flavors" of UCaaS: single-tenancy and multi-tenancy. With a single-tenancy approach, the customer receives a customized software platform that can be integrated with on-premises applications. Multi-tenancy customers share a single software platform. Enterprises can also adopt a hybrid approach, keeping a portion of their unified communications on-premises and other applications in the cloud.
Many companies, primarily small businesses, use UCaaS to avoid the capital and operational expenses associated with deploying a unified communications solution on their own.