Vaquero is basically Spanish for cowboy. Originally, cowboys were people who tended to cattle, however, popular culture changed them to gunslingers and similar.
Though popularly considered American, the traditional cowboy began with the Spanish tradition, which evolved further in what today is Mexico and the Southwestern United States into the vaquero of northern Mexico and the charro of the Jalisco and Michoacán regions.
And at the root of a popular Mexican event, called the charreada (rodeo), is the Mexican cowboy (vaquero). Today, a charreada is the competitive proving ground of a new type of Mexican cowboy, the brave and proud charro. ... The first vaqueros were Indians or mestizos.