How are dw and dd different from db directives for strings?

Question

Let\'s say I want to define a initialized variable string before running my assembly program (in section .data). The variable I chose to create is called

Answer 1

For each character in the string "0123456789ABCDEF" you need just one byte. So, the string will occupy 16 bytes in the memory.

In case of this declaration:

vark db 1

you can make this:

mov [vark],128

and cannot:

mov [vark],1024

but in this case:

vark dw 1

you can.