The Build Settings can be accessed from the File menu
by going to File - Build Settings.
A build in development is a term used to describe
an exported executable form of your project.
And given Unity's multiplatform nature
this varies for each platform.
For webplayers Unity will export an HTML file
with example embedding code
and a .Unity 3D file which contains your game
and will be run by the Unity webplayer plug-in
in your browser.
For standalone Unity will export an executable version of your game
for PC, Mac and Linux.
For iOS Unity exports an Xcode project
that can be opened in Apple's Xcode SDK
and run on the device for testing
and submission to the app store.
For Android Unity exports an APK file
that can be opened in the Android SDK.
Flash exports an SWF file
associated assets,
and yet again an HTML file with example embedding code.
Google Native Client exports a Google Chrome browser
compatible webplayer game.
And for consoles Unity builds directly to your
hardware development kit.
The build settings work with Unity's player settings
to define settings for the build that you create.
Split in to cross-platform and per-platform
you can set some basic values at the top and then choose settings below
that are specific for the platform you are developing for.
One thing to note as a beginner
is that the resolution in the Resolution and Presentation area
is the setting you can select for the game view.
For details of other per-platform settings
refer to the manual link below.
Subtitles by the Amara.org community