At first I thought a scheme was a list of values for each build type. By default, there are two schemes, Debug and Release. In the app target, you customize each scheme on the fly by choosing the values (in the default case for either Debug or Release).
However, now I think the schemes are bigger than that. Your project comes with one scheme by default, and included in that scheme is the ability to customize settings for different build types, including run, test profile, etc... So in ONE scheme you can have settings xyz for the run phase, and in ANOTHER shceme you can have settings abc for the run phase.
I'm a little confused here. Can anyone simplify this?
Thanks
From Xcode's Help:
scheme
A scheme is a collection of settings that specify the targets to build for a project, the build configuration to use, and the executable environment to use when the product is launched. When you open an existing project (or create a new one), Xcode automatically creates a scheme for each target. The default scheme is named after your project.
Here, "build configuration" is what you're calling "Debug" and "Release" above.