What is the meaning of aspect?

noun

• A distinct feature or element in a problem.
  • usage: "he studied every facet of the question"
  • synonyms: facet
• A characteristic to be considered.
• The visual percept of a region.
  • usage: "the most desirable feature of the park are the beautiful views"
  • synonyms: view, prospect, scene, vista, panorama
• The beginning or duration or completion or repetition of the action of a verb.
• The feelings expressed on a person's face.
  • usage: "a sad expression"; "a look of triumph"; "an angry face"
  • synonyms: expression, look, facial expression, face