In reply to The Ice Doctor:
One view is that they are simply a removal of "burdensome and unnecessary regulations/restrictions".
At their most benign, that could simply be a removal of import tariffs. End result is cheaper products, boosting consumption and money in the pocket and each country focusses on what its really good at. Downside would be local producers suddenly finding themselves being undercut.
On the other hand, burdensome regulation can come in the form of human rights laws, safety and environmental controls.
I can see the advantages in free-trade, and its obviously an ideal. But in the same way that free movement of people around the world is a goal we should aim for, while huge disparities in wealth and opportunity exist, it doesn't seem practical. I don't see how true free-trade wouldn't result in a race to the bottom in terms of wages, regulation and undermine all those annoying bits of legislation that actually allow us to live healthier and happier lives in the long-term.