dif·fer·ence 
(dĭfər-əns, dĭfrəns)
(dĭfər-əns, dĭfrəns)n.
1. The quality or condition of being unlike or dissimilar.
2.
a. An instance of disparity or unlikeness: There is a big difference in sound between a clarinet and an oboe.
b. A degree or amount by which things differ: a difference in height of three inches.
3. A noticeable change or effect: Exercise has made a difference in her health.
4. A disagreement or controversy: Let's settle our differences.
5. Discrimination in taste or choice; distinction: In this case, the law should make no difference between young and old.
6. Mathematics
a. The amount by which one quantity is greater or less than another.
b. The amount that remains after one quantity is subtracted from another.
tr.v. dif·fer·enced, dif·fer·enc·ing, dif·fer·enc·es
To distinguish or differentiate.
Synonyms: difference, dissimilarity, unlikeness, divergence, variation, distinction, discrepancy
These nouns refer to a lack of correspondence or agreement. Difference is the most general: differences in color and size; a difference of degree but not of kind.
Dissimilarity and unlikeness often suggest a wide or fundamental difference: the dissimilarity between human and computer language; attracted to each other by their very unlikeness.
However, dissimilarity is also used to emphasize the points of difference between things that are otherwise alike or comparable: an analysis of the dissimilarities between the two sets of data.
Divergence can denote a difference resulting from a branching or separation; alternatively, it can indicate a range of difference within a category: the growing divergence between British and American English; a large group with a divergence of opinions on the subject.
Variation occurs between things of the same class or species; often it refers to a modification of something original, prescribed, or typical: variations in temperature; a variation of a familiar technique.
Distinction often means a difference in detail determinable only by close inspection: the distinction between "good" and "excellent."
A discrepancy is a difference between things that should correspond or match: a discrepancy between his words and his actions.
These nouns refer to a lack of correspondence or agreement. Difference is the most general: differences in color and size; a difference of degree but not of kind.
Dissimilarity and unlikeness often suggest a wide or fundamental difference: the dissimilarity between human and computer language; attracted to each other by their very unlikeness.
However, dissimilarity is also used to emphasize the points of difference between things that are otherwise alike or comparable: an analysis of the dissimilarities between the two sets of data.
Divergence can denote a difference resulting from a branching or separation; alternatively, it can indicate a range of difference within a category: the growing divergence between British and American English; a large group with a divergence of opinions on the subject.
Variation occurs between things of the same class or species; often it refers to a modification of something original, prescribed, or typical: variations in temperature; a variation of a familiar technique.
Distinction often means a difference in detail determinable only by close inspection: the distinction between "good" and "excellent."
A discrepancy is a difference between things that should correspond or match: a discrepancy between his words and his actions.