Working with Builds, Schemes, and Workspaces - Xcode 4 - page 286

Understanding settings and options
There are five critical points to remember about projects and targets:
Projects and targets can have separate build options.
Build options are not the same as build settings .
Build options include information needed to make a target, including selected artwork files, supported
orientations, version numbers, property lists, and so on. They also include build settings.
Build settings are a list of low-level compiler, linker, and packager switches.
Target options override project options.
Xcode uses a priority hierarchy to calculate which settings and options to use when building a target. There's
more information about this later in this chapter.
NOTE
In earlier versions of Xcode, you could also define an executable— a context in which a product would run. In
Xcode 4, this option has been expanded and built into the new schemes feature, which is described later in this
chapter.
Understanding the project options