Subtraction is "taking away" or subtracting one number from another to find the difference.
7 - 4 = 3 means:
1. Subtract 7 by 4
2. Subract 4 from 7
When you do subtraction the answer you get is the difference
When you Subtract a number from another number you will get the difference of the numbers.
If you subtract a number by zero the difference will be the number itself
If the minuend and subtrahend are same, then the difference will be zero