Need help with BASH and DASH
 

I'm reading about "Bash" and "Dash"..?
In in a Google surf I read that Dash seriously messed-up someones Ubuntu OS...

I have a little red update-arrow on my desktop telling me I have a new update... It's Dash...
Is Dash a good thing, or a bad thing..?

dash is just another shell
 

dash is just another shell alternative to bash, like zsh and others. I don't think using it would cause any damage to your system, since in Ubuntu is sort of the default shell when you run scripts with the /bin/sh command (/bin/sh is just a symlink to /bin/dash.)

Since dash is a very lightweight shell, you must specify the bash shell in the script if said script uses any bash feature not available in dash, using a line like this:
as the first line of your script.