O.k, First you would need to understand what reputation is which can be found
Here. and when you give/take rep points it is stored at the bottom of your main UserCP page (See Attached Photo) at the bottom of the main page, you will find a table which records if you recived good (green), or bad (red) rep. This table records who gave/took it from you. The reputation comment is the comment that they gave for giving or taking rep. like in the picture, someone said "PD is a Nice Guy" which is a rep comment.
Hopefully that answers your question