The $ is used to fix the column or row. If you use $A1 in a formula and then copy that formula across row 1, the A will not change. If you use A$1 in a formula and then copy that formula across row 1, the A will change to match the column. If you use $A$1 in a formula and then copy that formula across row 1 and then down a few rows, both the A and the 1 will not change. If you use A1 in a formula and then copy that formula across row 1 and then down a few rows, both the A and the 1 will change. As you can see, the $ makes the column and the row fixed. Without the $, the column and row will change as you copy the formula to another cell or range.will take care of both
You can probably see by the responses that it does not take care of both. Depending upon how you use the A1 format as absolute or relative reference will determine how your formulas and data are manipulated, calculated and derived. The references are not the same and while you may be able to use one or the other is some cases, you cannot interchange them in all cases. I suggest that you hit the books and really learn what they mean.So why bother learning when I need to use $A1 or A$1 when $A$1 will take care of both?