You can install InCopy and other Creative Cloud apps on up to two computers. If you want to install it on a third computer, you'll need to deactivate it on one of your previous machines. To learn more about activating and deactivating Creative Cloud apps, read the article Sign in to activate your Adobe apps.
InCopy workflows allow multiple people to work on the same InDesign document simultaneously. Learn more about creating and using InCopy workflows.
A managed-file workflow uses the LiveEdit Workflow plug-in to manage changes to shared files among multiple users. Read this overview to learn more about a basic managed-file workflow.
An InDesign user can export content to InCopy, which creates a link between the two applications. You can open this shared content, or assignment, in InCopy, and then check out the content using the Assignments panel.
If you want to set up a workflow, but not everyone has access to the same server, you can create and distribute assignment packages instead of putting files on a shared server.
InCopy supports several graphic formats like PNG, JPEG, GIF, and so on. For the complete list, see Supported file formats.