I am wondering about Points https://en.wikipedia.org/wiki/Point_(typography) where DTP defined a Point as 1/72 Inches. Should I ignore Points and only consider Pixels and the Pixels per Inch because Lazarus only does that?
The D in DPI is a "dot". For screens a dot nearly always means a picture element or pixel. Screen pixels vary in size, and are not always square. A pixel refers to an item of hardware, and is not a measurement. Early cathode ray tube screens had pixels whose size was determined by the width of the electron beam that was aimed at a curved glass screen covered in phosphorescent materials.
For printers, a "dot" represents a splodge of ink, and the printer resolution determines the smallest splodge the printer can produce. The distance between printer dots or splodges is commonly measured in points, an ancient measurement, predating the computer era. A point is always exactly 1/72 inch. It is a measurement, not a specific item of hardware.