Why does simulator sdk provide more APIs than iOS sdk?
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I saw many frameworks available on simulator while not on iOS
E.g. /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/CoreServices.framework
doesn't have counterpart under 
/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/System/Library/Frameworks

What are they for? I suppose we shouldn't call any APIs from such frameworks.
