How would you describe the movement of products through a facility that contains our equipment?

"I haven't been inside a facility before, but I did some research before this interview. It looks like there are two main types of systems - First In First Out, or FIFO systems and Last In First Out, or LIFO systems. FIFO systems tend to be used for perishable items, such as food, whereas LIFO systems are used when the items won't go bad. From my research I saw that different types of storage rack are used in different systems, such as Push-Back rack is typically used in FIFO systems. What kind of system do most of your customers use?"