When you create a workflow, you can choose among various workflow steps to document your internal processes. Integrations enable powerful capabilities of some of the workflow steps.
File upload, for assignees to upload files from Box or Google Drive (e.g. for uploading HR documentation or project files).
Create a task, to trigger automated creation of a task on a project management tool (e.g. creating a task on Asana, issue on JIRA, or card in Trello, when a specific workflow step has been completed)
Post to channel, to trigger an automated notification to a Slack channel (e.g. to notify project members that a specific workflow step has been completed).