Geek vs Nerd

Example nerd interests for comparison:

1. Physics (such as Quantum Mechanics or Astronomy), Chemistry, Biology, Engineering and Fuzzy Math
2. Chess, Dungeons and Dragons and other strategy games
3. 17th Century English Literature
4. Classical music
5. International politics and CSpan stuff

Example geek interests for comparison:

1. Specialized forms of activities, such as 'tricking'
2. 'Niche' activities, such as electrical engineering
3. Noise music
4. 'Odd' activities, such as creating Rube-Goldberg machines
5. Computer Programming

Observe the person
Nerds are unabashed about using jargon or unfamiliar terminology in their dialogue whereas geeks will use obscure references abundantly. Geeks often take interest in the microcosmic details of life, such as noticing that your present situation is much like one from a news article or novel. Nerds will seemingly be uninterested in the details of daily life, being more focused on the macroscopic, such as scientific possibilities and the future of mankind.

Take a quick inventory of their prominent possessions, especially ones related to hobbies and other interests
Nerds may be more willing than geeks to show off hobbies and possessions that flaunt their intellect, whereas geeks may take pride in more obscure and unique subjects.

Engage the person in conversation.
Also, nerds may speak in layman's terms for your benefit because you may not understand the basic concepts of their area of interest. Geeks may speak in detail about their interests, possibly forgetting that the target audience may not have the same level of knowledge in that field as themselves.

Inquire about the person's interests.
Hobbies which do not elicit emotion, such as frequent studying of academics, are good indications of a nerd, while an obsession with the practice of academics (i.e a passionate college lecturer) would indicate a geek.

NOTE:
The interest of nerds and geeks often overlap. Most nerds enjoy the more intellectual forms of Science Fiction and most geeks have a higher knowledge of science or encyclopedic data than the general population.

To engage a geek or a nerd in conversation, be prepared to accept that there is something fundamentally interesting about what they obsess about. You may not fully understand why, but just accept that it is so.

Nerds may not feel the need to defend attacks against their areas of interest, since they simply don't care so much about others' opinions. Geeks are typically very energetic, and will jump at the chance to discuss a topic they care about.

The interests of geeks are often ridiculed or put-down by those who do not fully appreciate them. Nerds themselves are often ridiculed or put-down by those who do not fully understand them.

Some nerds believe that their interests are of "potential value to humanity as a whole, although humanity doesn't know it yet".

Geeks are typically able to extrapolate beyond an object's immediate value to foresee future value, although many will merely see a trinket, or garbage.

Generally, a nerd will become a scientist and a geek will become an engineer.

Nerds and geeks, by their very nature, shall never be 'mainstream' or accepted by the general populace. All one can do is attempt to be a little more open-minded, and a little more understanding of one another.

WARNING!!!

Geeks are well aware of their 'geekiness'. Many geeks are even proud of being a geek, hence the launching of sites such as ThinkGeek.com, LifeHacker, Gizmodo, and Engadget. Therefore, do not ever challenge a geek's level of 'geekdom' if you wish to converse with them. Likewise, do not question the intellect of a nerd, lest you be shunned from their conversations.

Many nerds and geeks are introverted, and some are even asocial. They may even not want to talk to you at all. Be patient when conversing with them.

Don't assume that geeks and nerds only have one interest. A linguist or artist may also happen to play football or guitar.

Nerds and geeks are often clever and witty. Enjoying the sci-fi channel or knowing the Constitution in Latin are not grounds for claims of inferiority.

Do not assume that nerds and geeks want to be 'converted' into 'popular' people. Despite popular misconception, nerds and geeks do not worship the popular, nor are they frightened by them.

Geeks are generally more open to talk things out with you if they disagree; a nerd will typically shun you, merely believing that you simply "don't understand."

It is possible for someone to be a nerd and a geek, depending on definition. For example, people who like Star Trek may be interested in NASA level quantum physics. A tomato gardener may have a degree in bio-chemical engineering. Many 'nerd' and 'geek' interests interlace. Often being a geek leads to being a nerd, as people research areas of science and technology appropriate to their interest. Similarly, nerds can become geeks, as expertise leads to interests outside the typically 'academic.'

Remember: Someone who calls themselves a nerd or geek may have a different definition of the term than you do. There are regional trends, but definitions should be examined on a person-by-person basis