what I asked may be answered, but I didn't find it

I read the thread and most of answer/tutorial are related to adding a new widget area in center post/page area, but I would like to know if I want to place a customized widget on the right sidebar for a particular posts category only, which atahualpa file do I need to edit it? Thank you for your time.


J.M

none, you need a plugin like 'widget-logic' or 'dynamic widgets'