The sticky browns were originally the sort of mixture that comes out of a cane sugar crystallising pan. In modern refining practice both of these types are made by mixing a refined or at least purified sugar with a suitable syrup. The colour of the sugar and the syrup determines the colour of the final product and the ratio of syrup to sugar plus any drying applied determines whether the product is sticky or free-flowing. Syrups, of which there are again an enormous range, range from pure sucrose solutions as sold to industrial users to heavily treated syrups incorporating flavours and colours. This helps ensure that crystallisation does not occur during storage.
Treacle is a similar product made from molasses rather than a pure sugar solution.