What is frontal gyri?

Some articles on frontal gyri, gyri:

Music-related Memory - Semantic Vs. Episodic
... memory involved activation in the right inferior and middle frontal gyri, the superior and inferior right temporal gyri, the right anterior cingulate gyrus and ... There was also some activation in the middle and inferior frontal gyri in the left hemisphere ... bilaterally in the middle and superior frontal gyri and the precuneus ...