Water, flour, yeast, and salt. That’s all there is in a traditional baguette. How do you know if you have bought a perfect baguette? Give it a long good smell. You know you have the perfect baguette if the crust gives off a caramely scent, while the white crumb has a milky odor, although neither caramel nor milk are used in making it.
A good baguette has a crunchy and brown crust, but for this same reason the baguette will go stale rather quickly. It is difficult for a baguette to last for more than a day. There has been an increasing demand for boulangers in Paris to undercook their bread (whiter and less crunchy crust) so that the baguette can keep longer and the customers who bought them can eat it the next day.
The word baguette means wand. There are a few stories behind the reason for the bread taking on this shape. The two most people referred to are 1) Napoleon requested to have the baguette in a long shape, so that his soldiers could carry their bread around down their pants while they were in battlefield. And 2) A law passed in 1920 that forbids Parisian bakers to work from 10pm to 4am. They opted for the longer thinner shape as opposed to a big round for it to cook faster and ferment quicker.