Difference between dried and preserved

DRIED FLOWERS : Flowers are dried out in a process where they are placed face down, or hung upside down in a shed, and left to dehydrate naturally. It takes around two to three weeks to dry flowers naturally. This time can be even less if the weather is hot. Please note that you should not remove flowers from their drying positions until they are completely dry.
Once the process is complete and they are completely dehydrated, the flowers and leaves are brittle to touch. 
Unlike dried flowers, preserved flowers undergo a much more technical process. After the fresh flowers are cut they are then placed, stem first, into glycerine (trihydric alcohol) to undergo a rehydration process. Glycerine (also called glycerol or glycerin) is a simple polyol compound. It is a colourless, odourless, viscous liquid that is sweet-tasting and non-toxic. The glycerine is absorbed by the flower, through the stem, until it substitutes the sap. After this process is complete, the plant is ready to be used. The final product remains soft and almost exactly like they were in nature.
After the flowers have been preserved you can then choose to change their original colour through the process of bleaching. To change the colours of the flowers you need to bleach them to remove all the original pigment. Two methods of bleaching can be used by a florist to create this look. The first method can be oxidative bleaching, which uses hypochlorite, chlorite, and peroxide chemicals, or the second method can be reductive bleaching, which uses sulphites, and borohydrides chemicals. Please note, the bleach products used throughout this process are no different to the bleach a florist would use on their flower buckets, daily. When the flower has gone through this process, subtle food dyes can be added to it to create on-trend pastel hues. The final product will remain soft and similar to its natural form.