The storage class specifiers are a part of the decl-specifier-seq of a name's declaration syntax. Together with the scope of the name, they control two independent properties of the name: its storage duration and its linkage.| en.cppreference.com
Definitions are declarations that fully define the entity introduced by the declaration. Every declaration is a definition, except for the following:| en.cppreference.com
C++| en.cppreference.com
This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21| cplusplus.github.io