viruses vs worms

Am I mistaking about any of the following?

  • viruses appeared before worms
  • viruses are harder to makebecause 1)they need to append code to a host file 2)they need to check to see if they have already infected a file
  • viruses are easier to remove than worms
  • worms are a standalone executable and do not infect files and do not require a hots file

I ask because why would anyone make a virus, why not just write a simple executable that does its job and exits?

I ask because why would anyone make a virus
It could be various reasons like because they can, profit, to be annoying, etc
viruses are harder to makebecause 1)they need to append code to a host file 2)they need to check to see if they have already infected a file
Niether one is any harder then another. It depends on what the coders goal is and what that person would like to accomplish, if it can be done
viruses are easier to remove than worms
I say it's about the same, until you start talking about bios rootkits :)
why not just write a simple executable that does its job and exits?
I can't answer that >:-D, Ask someone that writes code for that :■■■■