Now they both look long and slender, both are same color and unless they are blooming are difficult to determine whether one is buying garlic or regular chives. What is the difference?
Garlic chives have a flat leaf whereas your regular "put in the baked potato" chives are round. You can literally touch the leaf and feel the difference in them.
Generally speaking in our zone 7 the regular chive grows faster and spreads more than the garlic chive. Now if you like garlic though there is nothing, including garlic bulbs themselves, that compares to the flavor of a garlic chive blossom. Yes the flower is an edible flower and very intense. The regular chive has a blue flower while the garlic is white. You would not drop the entire garlic chive blossom into your food but you would take the separate florets and sprinkle them across the food such as in a fresh mesclun salad.
Also on chives be sure to always cut them from the base, not mid or high on the leaves. If you cut from the base the plant will start spreading out and growing back up. When you cut from the top the leaf dies down to the base. If after cutting from the base you have extra leaf left over do not chop it up but simply put the whole leaf in a freezer bag and freeze. Defrosting takes about a nanosecond. The reason for not chopping and then freezing is the chopping allows the oil to escape and when you extract from the freezer bag the flavor is left in the bag, not the leaf.