Comfort, console, solace are comparable when meaning to give or offer a person help or assistance in relieving his suffering or sorrow.
Comfort, the homelier, more intimate word, suggests relief afforded by imparting positive cheer, hope, or strength as well as by the lessening of pain and distress.
Console, the more formal term, emphasizes rather the alleviation of grief or the mitigation of the sense of loss than the communication of pleasure; it frequently implies some definite source of relief.
Solace frequently suggests relief from distressful emotions (as weariness, despondency, chagrin, loneliness, or dullness) rather than from grief or pain, and often, specifically, a lift of the spirits; the source of that relief is more often things than persons.