A package dependency enables a package target, or Xcode project, to use a product in another package. A package dependency is specified by a URL to the remote Git repository containing the package, and the versions of the package that are supported by the client. The format of a package version uses the Semantic Versioning specification, which is typically a three period-separated integer, such as 2.1.4.
For details on the version format, go to Semantic Versioning 2.0.0.