The Sombrero the traditional hat of Mexico
A Sombrero in Mexico is any wide-brimmed hat, although for most people outside the region it is also a hat with its brim upturned along its edge.
Its main function is the protection of the head and shoulders from the Sun.
Some like this one can end up highly decorated and are used by Mariachi folk music performers.
This I believe is a full Sombrero but in Mexico there are many types with names suchas Quinciano, Diechinueve, Veintiuno, Veintisiete, Traditional sombrero or modern sombrero.