Etcher Under Linux


I have been advised to use Etcher to burn an iso file to a pendrive to form a live pendrive, but I have some questions.

Will Etcher format the pendrive so that I will need to back up all the files that I have stored on the stick?

I can find no information regarding thes application. Is there a link?

When the advert says ‘its safe’, what does this mean?

The zip file looks large?

Does it install on my pc ready to form live pendrives, or can it be simply copied to a folder?. I hope that it does not need to be copied or installed to the pendrive.