What is the portrait mode

When creating a presentation in libre office impress, where does the editing of slides take place?

The basic work area of the computer is it screen that you when you first fire up your computer

Johnson enterprises uses a computer to handle its sales invoices. lately, business has been so good that it takes an extra 3 hours per night, plus every third saturday, to keep up with the volume of sales invoices. management is considering updating its computer with a faster model that would eliminate all of the overtime processing.