The Print Shop Manager main screen is the work area for the templates. From the button bar you can launch several templates at one time. The work area can hold more open templates than you would really want to work on at one time. But this allows you to get a quick price for one customer while working on quotes for two other customers (if you need to).
The completely open environment allows you to lookup customer information or pricing information while you are building a quote. You can look at completed orders while you are posting payments. There are actually very few limitations as to how many things you can do at one time.