A few years ago, if you wanted to use SharePoint for collaboration or Exchange for email or Lync for communication, you absolutely had to deploy hardware, install all of these servers and manage them yourself in addition to the rest of the on-boarding and deployment activities. Today, you have an option to not have to do that if you so wish. Microsoft provides these servers in a Software as a Service (SaaS) model under the Office 365 brand; and that is not all. It also saves you the hassle of granting your employees access to these resources on the go. In addition to that, you also get licenses for all of the Office software as well. No longer do you have to manage and track licenses separately.
This saves your business a lot of money and headache involved in managing these assets yourself. Microsoft updates their servers as patches come out and upgrades to newer versions with minimal to no impact on your deployment.