Well hopefully that's what it means, otherwise what's the point in growing it? I'd query that with the garden centre you got it from, just in case though.

Well Goji berries are meant to be better than most for supplying vital C and antioxidants and I can't remember what all else. The berries are most certainly edible.

Goji berries or the Wolfberry or Duke of Argyll's tea tree is a member of the Solanacea family which includes things like deadly nightshade as well as peppers, tomatoes etc. We eat tomato fruits but we'd get very ill if we ate the foliage.
I think it is highly likely therefore that the foliage of the plant is inedible, at least, and best avoided, though does anyone know if the Duke of Argyll actually made tea from the leaves or the flowers/fruit?
Although the Goji has become a cult plant recently, it can be found growing in hedgerows in the UK, and the 'wonder properties' of the berry are exaggerated. The average blackcurrant has just as much anti-oxidant and Vitamin C properties.