A framework is a hierarchical directory that encapsulates shared resources, such as a dynamic shared library, nib files, image files, localized strings, header files, and reference documentation in a single package. Multiple applications can use all of these resources simultaneously. The system loads them into memory as needed and shares the one copy of the resource among all applications whenever possible. (Apple)
What are SDKs?
The term “SDK” generally refers to a possibly large collection of frameworks and libraries. (StackOverflow)
What are Libraries?
A library is a set of code that was previously written, that can be called upon when building your own code. It is work that was previously done by someone else that you can now make use of, without having to do it yourself. And you can make use of it in your own code, legally, as it was written to be used by others. (Quora)
Static Libraries and Dynamic Libraries?
They both a Library, but the way our app uses them is different,
With Dynamic Libraries, the app loads code from the libraries into its address space when it’s actually needed, either at launch time or at runtime. Meanwhile, if we use Static Libraries, we need to load them to the app first when it starts, even though the app needs it now or later.