MUY RECIENTEMENTE EN EL OBSERVATORIO DE NEUTRINOS SOLARES (SNO) DE SUDBURY CANADA, DIERON A CONOCER LA PRIMERA EVIDENCIA EXPERIMENTAL DE QUE LOS NEUTRINOS PRODUCIDOS EN EL CORAZÓN DEL SOL CAMBIAN DE IDENTIDAD EN SU VIAJE HASTA LA TIERRA. LA EXPLICACIÓN MÁS PROBABLE DE DICHO FENÓMENO SON LAS LLAMADAS OSCILACIONES DE NEUTRINOS. EN EL PRESENTE TRABAJO DAMOS UNA INTRODUCCIÓN DIDÁCTICA A LAS OSCILACIONES DE NEUTRINOS, TANTO EN EL VACÍO COMO EN MEDIOS MATERIALES; DESTACANDO EN ESTE ULTIMO CASO EL EFECTO RESONANTE MSW. DICHO TRABAJO ESTÁ FORMULADO PARA EL CASO DE DOS GENERACIONES DE NEUTRINOS, SIN EMBARGO, DAMOS UN BOSQUEJO PARA EL CASO DE TRES GENERACIONES.AbstractRECENTLY THE SOLAR NEUTRINO OBSERVATORY (SNO) GROUP IN SUDBURY CANDA, SHOWED THE FIRST EXPERIMENTAL EVIDENCE THAT NEUTRINO PRODUCED IN THE SUN´S CORE, CHANGE THEIR FLAVOUR WHEN THEY PROPAGATE. THE MOST PROBABLY EXPLANATION OF SUCH PHENOMENON ARE THE NEUTRINO OSCILLATION. IN THIS WORK WE GIVE A PEDAGOGICAL INTRODUCTION TO NEUTRINO OSCILLATION, BOTH IN THE VACUM AND IN THE MATERIAL MEDIUM, EMPHATHIZING THE RESONANT MSW EFFECT IN THE MEDIUM. THIS WORK IS FORMULATED FOR TWO NEUTRINO GENERATIONS HOWEVER, WE GIVE A BRIEF SUMMARY OF THREE NEUTRINO GENERATIONS.RECENTLY THE SOLAR NEUTRINO OBSERVATORY (SNO) GROUP IN SUDBURY CANDA, SHOWED THE FIRST EXPERIMENTAL EVIDENCE THAT NEUTRINO PRODUCED IN THE SUN'S CORE, CHANGE THEIR FLAVOUR WHEN THEY PROPAGATE. THE MOST PROBABLY EXPLANATION OF SUCH PHENOMENON ARE THE NEUTRINO OSCILLATION. IN THIS WORK WE GIVE A PEDAGOGICAL INTRODUCTION TO NEUTRINO OSCILLATION, BOTH IN THE VACUM AND IN THE MATERIAL MEDIUM, EMPHATHIZING THE RESONANT MSW EFFECT IN THE MEDIUM. THIS WORK IS FORMULATED FOR TWO NEUTRINO GENERATIONS HOWEVER, WE GIVE A BRIEF SUMMARY OF THREE NEUTRINO GENERATIONS.