Geeks and nerds are two different types of individuals, though the words are sometimes used as a synonym for the other. While many become confused about the differences, both groups have unique traits that relate to their attitudes and actions. Understanding the differences will prevent accidentally insulting others with the inappropriate word.
As a general rule, geeks are the group that is hip and understands the trends in society. While the individual might not follow fashion, he or she is likely to have the latest popular innovations in technology and understands popular culture.
A nerd is the classic socially inept individual who is likely to spend time enjoying academic pursuits. While the individual is a little awkward socially, most are considered very bright and capable. In most cases, nerd is the term that has more negative associations, so most individuals prefer the term geek when it is applicable to the situation. While both groups are intelligent, the trendy nature of a geek differs from the absentmindedness of a nerd.
From: Masters In IT