It is the total carbs.

All carbs turn to sugar (glucose) when digested, so you need to factor them in.
So if a label says:
http://www.nhs.uk/Livewell/Goodfood/PublishingImages/food-label-white-bread_377x250.jpg
Then a single slice of this bread has 20g of carbs, of which 1.7 is sugar. In th UK, the fibre (which is also a carb, but does not raise blood glucose) is listed separately.
So for someone eating 20 g of carbs a day, that slice of bread is their entire carb intake for the day, leaving them only protein and fat as additional food.
On the other hand, if they didn't eat the bread, they could eat a LOT of vegetables before they had totalled up to 20 g of carbs.
For instance:
100g of green beans only have 3.1g of carb
100g of courgettes only have 1.8g of carb
100g of coleslaw only has 5.5g carb
100g of broccoli only has 3.2g of carb
100g of raspberries only have 4.6 g of carb
(all figs taken from the Tescos website)
This is why a well formulated low carb diet can contain a fantastic range of highly nutritious veg.
