In traditional Buddhism four senses of the word "mara" are given.
Klesa-mara, or Mara as the embodiment of all unskillful emotions.
Mrtyu-mara, or Mara as death, in the sense of the ceaseless round of birth and death.
Skandha-mara, or Mara as metaphor for the entirety of conditioned existence.
Devaputra-mara, or Mara the son of a deva (god), that is, Mara as an objectively existent being rather than as a metaphor.