Moving, impressive, poignant, affecting, touching, pathetic are comparable when they mean having the power to excite or the effect of exciting deep and usually saddening and solemn emotion.
Moving, the most general of these words, can be used in place of any of the others; the rest, though not mutually exclusive in their implications, can be used very specifically.
Something moving stirs one deeply or evokes a strong emotional response (as by thrilling, entrancing, agitating, or saddening).
Something impressive imposes itself forcibly on the mind and compels a response (as of admiration, awe, wonder, or conviction).
Something poignant produces so painfully sharp an impression that it pierces one's heart or keenly affects one's sensitivities.
Something affecting moves one to tears or to some similar manifestation of feeling.
Something touching arouses tenderness or compassion or melts the heart.
Something pathetic moves one to pity. Sometimes the word suggests pity induced by compassion for one in sorrow or distress.
Sometimes it suggests pity mixed with contempt for what is weak, inadequate, or futile.