Yes as was mentioned twice, it is based on a poem by José Martí, a Cuban nationalist poet and independence hero.
In the original lyrics, the author referred to a "guajira guantanamera"
(a peasant girl from Guantánamo), but since the song itself is
structured as a guajira (the Cuban rhythm, named after Cuban peasants),
some people think that the chorus refers to the song itself (or, rather,
its rhythmic structure), and not to an individual person.
In other words, the words are interpreted as an introduction to a
"guajira, Guantánamo-style" (which is part of Cuba -- thus a Cuban
style).
The song became a popular use as romantic, patriotic, humorous, or
social commentary lyrics, in Cuba and in the other Spanish speaking
parts of the world.
