Higher numbers are roughly equivalent to insistence.
For example:
> kill -1 3498
This roughly means 'maybe stop the program, if you can, maybe reload'.
Or the famous:
> kill -9 3298
This means 'kill the program dead, now, no questions, dead'.
**Beware** - if Firefox starts another program to connect to the internet, and you `kill -9 firefox`, this will leave all of Firefox's internet connection programs ("children") still there, but dead and useless.
- A dead program which sits there doing nothing is known as a 'zombie'.
- A program which is run by another program is called a 'child program'.
- A child whose parent program is dead is called an 'orphan'.
- A child who remains running despite being useless because the parent is dead is called an 'orphan zombie'.