Integrating Slack with Nuacom allows users to receive notifications about incoming calls and voicemails directly in Slack, as well as allowing them to make and receive calls through the Nuacom phone system using the Slack interface. To set up the integration, users need to install the Nuacom app in Slack and connect it to their Nuacom account. Once the integration is set up, users can configure the settings to receive notifications for specific events, such as missed calls or voicemails, and can also set up call routing and other phone system settings directly from within Slack.