These were the potters who lived at Netaim and Gederah. They lived there in the service of the king.
We may observe in these verses, 1. That here is a whole family of craftsmen, handicraft tradesmen, that applied themselves to all sorts of manufactures, in which they were ingenious and industrious above their neighbours, Ch1 4:14. There was a valley where they lived which was, from them, called the valley of craftsmen. Those that are craftsmen are not therefore to be looked upon as mean men.
Commenting on 1 Chronicles 4:11-23
These were the potters,.... Or are the potters; the posterity of those men, who were so famous in their day, are now of mean employments: some of them made earthen pots; and some of them dwelt among plants and hedges; or were employed in planting gardens and orchards, and making fences for them; or, as others think, "dwelt in Netaim and Gadara", cities in the...
These [were] the potters, and those that dwelt among plants and hedges: there they dwelt with the king for his work. (g) They were David's gardeners and served him in his works.