You have a choice of size and flower variety in the bags.
Lavender has a subtle floral scent and has calming qualities and can be tucked under your pillow to aid sleep.
Lavandin has a notably stronger scent due to the higher camphor content and is more uplifting and can be nestled amongst your finest knitwear to repel moths .
If you are now wondering which you have in your garden; as a general rule Lavender flowers earlier, and has more delicate flower spikes and Lavandin flowers as late as August into September and has thicker long flower spikes.