The Apple Lisa was the first personal computer with a GUI (Graphical User Interface). Before the Apple Lisa all computers used command line interfaces for every task even for simply moving a file from A to B. So when the Apple Lisa came on the scene with its window-based environment, page white screen, mouse and preemptive multi-tasking it caused quite a stir (partly because some people claim that Apple stole the ideas from Xerox).
The very first Lisa had two internal disk drives, a 5.25" and a 3.5" plus a huge external 10MB hard drive and 1MB RAM. At the time this was groundbreaking stuff and had the price tag to match. In 1983 the Apple Lisa would set you back $9,995 but for what you got this was a good price. RAM alone cost $4 per Kb back then!!