What does "storage-class information" mean in __declspec()?

Question

I am reading the MSDN article about __declspec.

It starts with:

The extended attribute syntax for specifying storage-class information uses the __declspec keyword, which specifies that an instance of a given type is to be stored with a Microsoft-specific storage-class attribute listed below. ...

What exactly does storage-class information mean? And how does it affect the compiler?

ADD 1

Someone posted a link as comment but deleted it soon after. I found the link useful. So I add it here.

http://en.cppreference.com/w/cpp/language/storage_duration

Answer 1

It appears that the article uses the terms "extended attribute" and "storage-class attribute" interchangeably. These terms simply refer to the attributes that you can specify inside __declspec(...).

Each attribute has its own meaning and they are mostly unrelated to each other. You can follow the links from the article to read about what each attribute does.