Power Platform Community Forum Thread Details

I suppose this is more of a SP question than Power Apps. But I have a Power App and I'm connecting to SP. I see on my SP site contents 3 lists, (2 lists and 1 event list). My question is simple - why the difference in the icon? does it mean different types of lists?
The #3 list I created from an Excel file, writing/exporting - Table, Export to SP. I honestly can't remember how I did List #1.