Grendel and Beowulf are both warriors, but they differ in several key ways.
First, Grendel is a monster who terrorizes the town of Herot, while Beowulf is a heroic warrior who comes to their aid. Second, Grendel is motivated by hatred and revenge against Hrothgar’s people, while Beowulf is motivated by a sense of duty and honor. Third, Grendel is a creature of darkness and despair—but Beowulf is a symbol of hope and courage. Fourth, Grendel lives in isolation from others; he has no friends or allies, but Beowulf is a leader of men and has many loyal followers. Fifth, Grendel prowls around at night; he fears no one because he believes himself to be invincible in his own domain—but Beowulf goes about his work during the day when most people are able to see him clearly. Sixth: Grendel is feared by all who know of him—but Beowulf is respected and admired by all who know him personally (including his enemies). Seventh: Grendel is a creature of destruction—but Beowulf fights for good causes as well as personal gain.