I'll give you a quick definition of each of these:
- voice: a vague term that is used to describe the specific features of a written work and how its told; the characteristics displayed by the narrator or speaker: usually analyzed in terms of tone, style, or personality. Not to be confused with point-if-view.
- mood: the emotional aura invoked by a work, synonymous with atmosphere.
- tone: the speaker's attitude toward his/her subject.
- theme: an abstract idea that emerges from a work; the ideas revealed by a work. Not to be confused with one-livers that tell a reader how to live.