What are the most obvious connections and differences between the SDK, API, and class libraries?

Supportdevelopmentkit. The adjective supportdevelopment describes the name of Kit, which is a combination of asuite of tools.

the SDK is the kit, the Toolbox,theIOS platform is XCode, a series of tools to combine together, For example, when you hit the code in the editor it will automatically complete the code, automatic error checking, you click run, it will call the compiler to automatically compile, compiled it will call the IPhone simulator to run , this is the SDK, which provides a complete set of development tools for developers to use.
Api:applicationprogramminginterface. The foothold isInterface, is the specification of an interface. Unixhave aPOSIX,Windowshave aWin32API, the function of writing a library of its own is the library'sAPI, you need to provide anWebservice needs to define its ownAPI. So it involves aSDKand the class library are different is, strictly speakingAPIjust give the interface specification without implementation, (of course, not even a realization ofAPIthat's not worth it, but it's also true in reality. So for example ,OpenGLhave their ownAPI, but in fact the support of the various families will be slightly different,POSIXThe same is true.
class Library: The literal meaning can only be an object-oriented code base. a set of SDKs can have multiple class libraries, and a class library can say that it implements an API.

API (Application Programming Interface)translation into Chinese is"Application Interface", in fact, this translation is not good, should say is"Program Communication Interface". Translation to interface, as the name implies to communicate two different things to use, usually composed of a set of function library. Two different things under one platform(programorsystem), in order to be able to take the other's function and so on, so aXThe program writes a set of functions that allow other programs on the same platform to takeXThe function of the program, the set of functions can be said to be thatXprogram is open to theAPI. For example, I want to add to my Web pageGoogle Mapthe functionality of the Web page is used"Google Map API". Nobita Games, professional Game API interface. Satellite public number: Dashinggames

What are the most obvious connections and differences between the SDK, API, and class libraries?