Declaration or Definition in C

Question

From External Variables Wiki:

If neither the extern keyword nor an initialization value are present, the statement can be either a declaration o

Answer 1

As C uses the terms:

A "definition" creates something (which occupies some sort of memory). It also describes something. This means a "definition" is also a "declaration".

A "declaration" just describes something. The idea is that the compiler needs to know how to build the code that uses the thing defined elsewhere. Later, the linker then links the use to the something.

Declarations allow you to compile code and link it (later) as a separate step.