First of all, what are cell styles? Will these allow you to quickly format a cell by choosing predefined cell styles. So for instance, you don't have to go into the cell and make it bold, then go into the cell again and underline it, and go into the cell again, and then make it italic. What you've got is one cell style, and when you apply that, it applies all of the attributes of that cell style in one go. What are the benefits of this? We end up with consistent formatting. I can choose that cell style, and apply it to one cell, five cells, hundreds of cells or all cells. The great thing about this, it can be done very quickly, but even better, let's say your boss says to you, "Hey, I love your cell styles, but the blue is not doing it for me. Can you just change it to green?" Well, you can modify that cell style, change it from blue to green, and all cells that have had the style applied to it, will change as well. So, something that would've taken you hours, now is done in just a few seconds. In terms of use, you can use Excels built-in cell solve, that's pretty cool. However, if you do want to create your own then that does require a little bit of setup, but once it's done, it can quickly be applied. So, that time invested at the beginning, well worth it.