Is it true that if you only go online to do normal things these computers are not for you? Also what are the differences between a computer powered by Windows and those that are not?

My first computer was in the nineties when they were called Macintosh but I did not have internet (did not even knew it existed) and I only played the few games, draw a few things once in a while and wrote my stories with it.

If I stay with Windows powered computers are Dell any good or should I stick with the others?