Breads in such a long form as the baguette (a baguette cannot be a baguette unless it is between 55 and 65 cm long) didn't appear in French bakeries until the 17th cen., and the baguette itself appeared on the scene well after the 18th cen. and even then it was only baked in the cities. It wasn't until the 19th cen. that the baguette was available even in the countryside.
Apparently there are about 12,000 bakeries in France that make bread for its 67 million inhabitants -- but what's more, about 320 baguettes are consumed and produced in France PER SECOND (that makes 10 billion baguettes a year)!!!! For those who think in terms of weight, it's about 180 g per day. According to Le Figaro in a 2008 article, 80% of the bread bought in France is the baguette.
The canonical French baguette became so industrialized with many consumers going for the industrialized and worse quality baguette that the smaller bakeries demanded something to be done. In 1993 Prime Minister Édouard Balladur announced a decree (Décret n° 93-1074) which distinguished the industrialized baguette from la baguette « tradition » for the consumer to protect the artisanal bakeries. (Oh, and in 1995, the decree Raffarin came out which defines "a real bakery" to distinguish the "bakeries" that don't prepare anything other than putting already prepared doughs in the oven, which was happening -- kind of like bakeries buying Pillsbury from the supermarket but here some were sourcing doughs from Polish bakeries to reduce costs)
Despite the better quality, la tradition is only about 25% of the breads sold in France (it is slightly more expensive, of course).
"La tradition" (in contrast to the "classique" which is what you get when you ask for a "baguette") has to
be baked at the bakery where it's sold (« cuit sur place »)
never been frozen
contain only flour, water, salt and yeast or starter -- i.e. no additives (EU regulations allow the classic to contain the likes of ascorbic acid, gluten, colorings, preservatives, emulsifiers, and thickeners. The classic actually can contain up to 14 additives)!
slow rise (long temps de fermentation) of 15-20 hours at 4-6°C (a normal baguette is usually left to rise only 3-4 hours at 20-29°C so more can be produced)
Taste difference between la baguette tradition and the la baguette classique -- the baguette (classique) is drier, less alveolated, and the crust is thinner and usually more floury.
Watch how a baguette is traditionally made in this video put out by the CREBESC (literally: Center of Research and Studies of the Bakery and Mentorship).
Along with this decree, flour mills offer branding services to bakeries -- for a subscription fee on the order of €10/month, they offer brand the tradition that the bakery sells to reassure their customers of the quality of baguette de tradition they are getting. Not only do the bakeries get the name AND the exact recipe to use, but also the packaging/bag, training, store propaganda props....for this reason, you will see bakeries selling their baguettes under brand names like Baguepy (Groupe Soufflet), Banette (one of the first, started in 1982 and is an association of about 40 flour mills under Euromill, a branch of Champagne Céréales), Blondinette, Campaillette Grand Siècle (sounds like the Rolls Royce of baguettes de tradition -- not sure if it is -- of Grands Moulins de Paris), Festival des Pains or its "red label" (elite) version Festive, or Rétrodor (1989). The Rétrodor (of the Viron Mills) is closer to the pre-war baguette and weighs 300g instead of 250g.
So. When you go to a bakery, if you ask for a baguette you might be getting one that has been industrially produced. Ask for une tradition or une tradi if you want to be sure that it is a baguette made following the 1993 decree.
And you can also ask for different types of degree of baking like for your steak -- bien cuite for one that has been baked longer, and pas trop cuite for a baguette that has been baked less.
Check out my survey of baguettes from the bakeries in Caen.