Define.. want to understand

Can we define a constant to our SFR like below???

&

supose i define a constant x = PORTB,3 like below
if i change the the value of x then the whole PORTB will effected or just bit 3 of PORTB will be effected??

what will be the result ???
OR

In your case, occurance of "x" will be replaced by "PORTB,3" before the source file is processed by assembler or compiler.

If you change the #define to other things, "x" will be substituted by other thing too.

You code does not make sense.

because it substituted into "movwf PORTB,3" and movwf moves 8-bit at a time.

Your remaining questions have nothing to do with the above ASCII replacement.

If you want to change PORTB,3 use
bsf PORTB,3 or
bcf PORTB,3

Essentially all define and equate do is a simple text substitution during assembly, as do those in the inc file. In your example, because it makes no sense, the assembler will generate an error.