ABBH Chin Ups Question

This is going to sound very retarded, but what grip and what width should i be doing the chin ups at on abbh1?

I always seem to hear people saying pull ups, chins, chin ups etc. But what are the differences? I know you can have multiple grips and widths so just wondering if anyone has a definitive answer. Even on websites ive looked up one guys chin ups are different to another… confusing as hell.

I tried the search but only found countless posts on failing after 5 reps etc… not much help.

When I did ABBH1 I used a pronated (palms facing away from the body) grip for variable widths. From what I know, a pull up is using pronated grip and a chin up is using supinated (palms towards self) grip. Even though the program had called for chin ups, I decided to do pull ups because I’m not as good at them.