Sometimes you might not want to develop a software component on your own and just want to use an existing one. Software as a Service (SaaS) basically gives you a hosted application. With SaaS, you don't need to worry about either the infrastructure or the platform built upon it, and not even about the software itself. The provider is responsible for installing, running, updating, and maintaining the whole software stack, as well as backups, licensing, and scaling.
There's quite a variety to what software you can get in the SaaS model. Examples vary from office suites such as Office 365 and Google Docs to messaging software such as Slack, through Customer Relationship Management (CRM) systems, and span even to gaming solutions such as cloud gaming services, allowing you to play resource-hungry video games hosted on the cloud.
Usually, to access such services, all you need is a browser, so this can be a great step in providing remote work capabilities...