life

人生(じんせい)	Life, as in someone’s entire life, or life in general:. “He lived a quiet life.” “Life is a bitch.” “Life span.”

命(いのち)	Life, as a particular person’s life spirit:life-or-death. Life as in a single thing that can be given, taken, lost, etc:“Your money or your life!” said the robber. The doctor’s emergency surgery saved her life.

生命(せいめい)	Life – as in biology. Usually used about the beginning or ending of life. “The beginning of life is a miracle!” “xxx lives were lost in the fire.”