As the name "Herbes de Provence" is generic, and not a Protected Geographical Status, there is no guarantee that Herbes de Provence come from Provence; indeed, the vast majority of these blends come from central and eastern Europe, North Africa, and China.
Herbes de Provence are used to flavour grilled foods such as fish and meat, as well as vegetable stews. The mixture can be added to foods before or during cooking or mixed with cooking oil prior to cooking so as to infuse the flavour into the cooked food. They are rarely added after cooking is complete.
Herbes de Provence are often sold in larger bags than other herbs, and the price in Provence is considerably lower than other herbs.
Provençal cuisine has traditionally used many herbs, which were often characterized collectively as "herbes de Provence", but not in standard combinations, and not sold as a mixture:
...the famous mixtures of herbes de Provence... were unknown to
my Provençal grandmothers, who used, individually and with discernment, thyme,
rosemary and savory gathered in the countryside.
It was in the 1970s that standard mixtures were formulated by spice wholesalers, including notably Ducros in France (now part of McCormick & Company).