UPC Barcodes, please help me understand

Hello all!

I am very new to this, so all advice is very appreciated. While setting up my store, one of the questions was if my products would have “Universal Product Codes.” I looked this up and it looks like a barcode. Is that correct? do I need to get a label maker? Also with the FBA model, I was under the impression I would never actually come in contact with the product. Please help me understand UPCs and how they play into setting up a store. Thank you.