Where did you get the tune? That might help as well.

As Jack Campin notes, they are genres, so your title doesn't make sense.
Cantiga- a poetical composition divided into strophes, after each follows a refrain.
Villancico- a metric composition sung in churches on certain festivals; a Christmas carol.

The above are the basic definitions in Velasquez, but some composers stretched the definitions.
Having formed a liking for older Spanish and Latin American music, I have many villancicos and cantigas on disc, by Jordi Savall and Hesperion XX and XXI, and others, baroque and older.