A connotation is a commonly understood cultural or emotional association that some word or phrase carries, in addition to its explicit or literal meaning.
A connotation is frequently described as either positive or negative, with regard to its pleasing or displeasing emotional connection. For example, a stubborn person may be described as being either strong-willed or pig-headed; although these have the same literal meaning (stubborn), strong-willed connotes admiration for the level of someone's will (a positive connotation), while pig-headed connotes frustration in dealing with someone (a negative connotation).
"Connotation" branches into a mixture of different meanings. These could include the contrast of a word or phrase with its primary, literal meaning (known as a denotation), with what that word or phrase specifically denotes. The connotation essentially relates to how anything may be associated with a word or phrase, for example, an implied value judgement or feelings.
It is often useful to avoid words with strong connotations (especially pejorative or ones) when striving to achieve a neutral point of view. A desire for more positive connotations, or fewer negative ones, is one of the main reasons for using euphemisms.
The denotation of this example is a red rose with a green stem. The connotation is that it is a symbol of passion and love – this is what the rose represents.
The denotation is a representation of a cartoon heart. The connotation is a symbol of love and affection.
In logic and semantics, connotation is roughly synonymous with intension. Connotation is often contrasted with denotation, which is more or less synonymous with extension. Alternatively, the connotation of the word may be thought of as the set of all its possible referents (as opposed to merely the actual ones). A word's denotation is the collection of things it refers to; its connotation is what it implies about the things it is used to refer to. The denotation of dog is (something like) four-legged canine carnivore. So saying, "You are a dog" would imply that you were ugly or aggressive rather than stating that you were canine.