Bridal Shower Question

Hi ladies, I'm clueless about bridal showers. Can anyone explain what's the purpose and how many people or who should be invited?

I'm having the wedding and my maid of honor asked about this 'cus she will help me plan it,but I'm clueless as to the proper etiquette.

I'm asian and FH is Italian/German American. Should I even have one? :(