The first variation of the mov instruction is to move a constant (or immediate value) into a register. In the following examples, ; (a semicolon) indicates the start of the comment; anything after the semicolon is not part of the assembly instruction. This is just a brief description to help you understand this concept:

mov eax,10  ; moves 10 into EAX register, same as eax=10
mov bx,7    ; moves 7 in bx register, same as bx=7
mov eax,64h ; moves hex value 0x64 (i.e 100) into EAX