Working with Builds, Schemes, and Workspaces - Xcode 4 - page 282

Projects: A project is a collection of source files that you can select and change using the editing tools in-
troduced earlier in this topic.
Workspaces: A workspace is a container for one or more projects. Previous versions of Xcode were
project-based. However, developers often need to work with source files in a more open way. It's not unusu-
al to use combinations of files from the same code base in multiple related projects. Workspaces make it
easy to do this. All projects in a workspace share the same build space, and you can use Xcode's build fea-
tures to define how the sources are combined. Potentially you can also build multiple projects with a single
build operation.
Targets: A target is a recipe for building the files in a project, and it defines its product—for example, an
app or a framework. By default, a project includes a single target. You can add further targets, as needed.
Note that a target doesn't have to be a finished app. You can also create targets that process code in other
ways—for example, to run a selection of optional test macros to check that important features work cor-
rectly.
Products: A product is the collection of files created by a target: an app, framework, test build, and so
on.
FIGURE 12.1
The components of the Xcode build system
Build actions: There are six standard actions, as shown in the figure. Build actions select one or more
targets, build them, and then run them through further Xcode features. For example, the Run action loads
the code into a runtime environment and launches a debugger, and the Analyze action runs the code
through an analyzer to check for basic errors.