Using a closer grip your working more of your bicep/ shoulder region.
Using a further apart grip your working your traps and your pectorials i find.
Ofc this is a good thing, but once you get above 20 or so reps, you wont be building up strength.
I suggest you use this as PART of a muslce group workout, so if your training biceps that specific day.
Do 5-7 excersizes with the closer grip being one of them, id suggest 3-4 sets involving 6-14 reps depending on how you find it, if it is getting to easy attach some weights to you etc.
But if your looking for strength your best of educating yourself first tbh.