what is the difference between "constexpr" and "static constexpr" variables of the non-class type in a header file?

I have a header file test.hxx which will be included in multiple translation units. The header file is as below:

namespace program_exec
{
static constexpr int DEFAULT_VAL = 0;

static constexpr char *name = "proc_exec";
}

I have included this header file in multiple translation units (*.cxx) and it works fine.

But removing the static infront of constexpr char* causes a linking error i.e, if I change the static constexpr char *name = "proc_exec" to constexpr char *name = "proc_exec";

I am getting a linker error saying that

error: multiple definition of program_exec::name

But making the same change for integers works fine i.e, changing static constexpr int = DEFAULT_VALUE; to constexpr int = DEFAULT_VALUE;.

Does difference does removing the static** infront constexpr int and constexpr char* makes?

Please help me in understanding the difference. Thank you very much in advance.