carthage:tldr:61914

The command "carthage update" is used in the Carthage dependency manager for iOS projects. Carthage is a popular tool used for managing external dependencies in iOS projects.

When you run "carthage update" in the terminal, Carthage will analyze the Cartfile or Cartfile.private file in your project directory. These files contain lists of dependencies and their specific versions or version ranges that your project relies on.

After analyzing the dependencies, Carthage will check if these dependencies are already present in your project's "Carthage/Build" directory. If they are not present or if the versions need to be updated based on your Cartfile, Carthage will download or update the necessary dependencies.

Once the dependencies are updated, Carthage will build the framework binaries for each of the dependencies specified in the Cartfile. These frameworks will be stored in your project's "Carthage/Build" directory.

Overall, "carthage update" is responsible for checking, downloading, and building the specified dependencies in your iOS project.