Your Wishlist, which is found under the little heart icon on the top right corner of the home screen, stores all of the items you fancy. While this list keeps your favorites top of mind, it doesn't keep them from being ordered by anyone else.
In the same way, when you place items in your bag but don't order them, they aren't reserved or placed on-hold. Someone else can still order these items even if they're in your cart.
If this happens, you'll be alerted at the cart page that the product is out of stock. To keep this from happening, hurry and snap them up!