13" MacBook refers to any Laptop Bags, Laptop Backpacks, Laptop Messenger Bags, Laptop Sleeves, Laptop Totes, or Laptop Cases that will hold an Apple MacBook that measures 13 inches.
About Briefcases:
Briefcases are box-shaped bags that have handles (may have on one side or two) and may have shoulder straps. Briefcases are most often known for their use by professionals to carry important documents. Briefcases may also be designed to carry laptop computers.
