What is the difference between a word's denotation and connotation? (site 2)

The term denotation refers to the specific meaning of a word, while the term connotation refers to the idea that the word invokes in a person.

Denotation and connotation must not be confused. Denotation is the primary or direct meaning of a word and connotation is its second meaning, that is to say, connotation is the idea implied by that word, which has not been made explicit as the primary meaning.  

Most times, connotation is influenced by the cultural experiences of individuals and that is why some words have a more negative connotation than others. For example, telling a young girl that she has an "immature attitude" might sound more offensive than telling her that she has an "adolescent attitude" since the word "immature" invokes a bad feeling and; therefore, it has a negative connotation.