Is the ubuntu system I am using distributed free of charge

I installed my system with this file:

ubuntu-14.04.3-desktop-amd64.iso

md5:

md5sum ubuntu-14.04.3-desktop-amd64.iso

cab6dd5ee6d649ed1b24e807c877c0ae

I just want to make sure that this file is distributed free of charge, and is not a pirated copy. This might be a dummy question, but I am not familiar with the new system yet.

Ubuntu is a free software. It is perfectly legal to redistribute it or/and modify it. You can this question for more info: Under what license is Ubuntu? Can it be legally modified and distributed?

So when you see Ubuntu, even modified one, it is probably legal.Such popular distros as Linux Mint,Elementary OS,etc. would not exist if Ubuntu licensing didn't allow modifying and distributing it freely.

Yes, according to here, this file is the official version.

source

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