Assembly square brackets

Question

I always wondered what the difference between

mov esi,eax 

and

 mov [esi],eax 

It was.

Any help is appreciated.

Answer 1

mov esi,eax writes the contents of the eax register to register esi .

mov [esi],eax writes the contents of the eax register to the memory address specified by the esi register (for example, if esi contains the value 0x1234, eax will be written to the address 0x1234).