Multitasking
It’s amazing how far computers have come in the past 10 years. I remember when decoding a single JPG image took several seconds on my 386 CPU (that was around the same time I was dreaming about having a 1GB hard drive some day…). Even 7 years ago, encoding MP3s still took a many minutes per song and rendered the PC virtually unusable for anything else. Watching (or even encoding) movies on the PC was not even conceivable....