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At the top center is the prominent image of the body graph.
The Body Graph
The body graph is the integrative field where the results of the database calculations are made visible. Each of the 64 hexagrams has a place in one of the body graph’s nine centers, called a gate. Pairs of gates connect centers through channels.

The Database
The database is the area of dates, times and numbers below the body graph (the central image) of a chart. It contains the calculations based on someone’s birth data.

The black Personality row displays date, time and place of birth and the planetary positions at that time indexed into the hexagrams and lines of the I Ching. This is a person’s conscious potential.

The pink Design row displays date and time of the Personality crystal (the “I”) entering the fetus, 88° of the Sun before birth, when the body is ready for consciousness. The planetary positions at that time are also indexed into the hexagrams and lines of the I Ching. This is someone’s unconscious potential.

The results of the Design calculation are transferred to the body graph by coloring half of the channel pink. The Personality calculations are transferred the same way in black. Personality and Design together result in pink/black stripes.

Centers
The crystals inform nine centers, hubs of awareness, information and energy throughout the body. They equal the seven chakras plus two whole-body awareness fields. Experientially known to us all, these represent the major nerve plexi in our own bodies.

Four of the centers are “motors,” energy hubs.

Head With only three gates, the Head center provides mental pressure and inspiration.

Ajna The mental awareness center conceptualizes thought.

Throat Communication, expression, action and manifestation are the Throat’s attributes.

Ji The seat of the Magnetic Monopole is the center of identity, direction and love.

Spleen This awareness in the Now is body con­sciousness, the immune system and well­-being.

Heart Motor. Material support, ego, will, courage, loyalty and competitiveness are its themes.

Solar Plexus Motor. The emotional energy in human life is emerging as an awareness.

Sacral Motor. The generating power of the Sacral center is vitality, sexuality, chi and life force.

Root Motor. Survival is the theme of the Root, the driving force of all life processes.

Channels
Centers interact and exchange information through the 36 channels. Channels are transforming agents, connecting the qualities of the centers involved into a distinct unit through which that information operates.

Gates
At both ends of a channel, at the junctions in the centers, are 64 gates. They correlate with the hexagrams of the Chinese I Ching and the math of the genetic code. When planets transit, they activate the gates in the body graph. The states of the gates at the moment of birth are the imprint that constitutes an individual human Design.

The 64 hexagrams of the I Ching are the maximum combinations of eight trigrams with each other. They describe the archetypes of experience, the attributes, experiences and pitfalls of human life. For thousands of years, its wisdom and guidance have been used for advice and comfort, warning or assurance. It encourages an approach of mindfulness of the individual, as it relates to family, community, state and God.

Definition
When planets activate gates at both ends of a channel, the entire channel is colored. This defines the two centers it connects and is called “definition.” Definitions operate consistently in the life according to the planets, gates, channels and centers involved.

The white, open areas in the body graph are the conditioning field, where people are attracted to and interact with others, learn their life lessons, gain expertise and wisdom, but also where protective defenses are built and habits maintained.

Definition Types
In the chart, definitions can be split from each other or connect. There are five possible configurations:

No definition No colored centers.
Single definition One or more channels continuously connected.
Split definition Two areas of definition separated from each other.
Triple split Three areas of definition.
Quadruple split Four areas of definition.

The Modes
Four of the centers are motors, energy centers. When a motor is defined and connected to the Throat through a continuous definition, the person can “do.” The energy is always available and can express itself.

If the Throat center is undefined or defined but not connected to a motor, then the person must “wait” for connections with other people or transiting planets that will enable access to action.

There’s only one type of Design with a mode “to do,” but three types with modes “to wait.” The two modes, to do and to wait, are further described as four basic types, identified by how the centers are colored and connect:

Reflectors have no definition at all. They reflect who they are with and mirror other peoples’ qualities. All people have Reflector aspects in their Designs (everything that’s white in the body graph). A Design “to wait.”

Projectors have definition, an undefined Sacral center and no motor to Throat definition. A Design “to wait.”

Generators have a defined Sacral center. Without a connection to the Throat, this is a Design “to wait.” With a connection to the Throat, this is a Design “to do,” a “manifesting generator.”

Manifestors have a continuous definition from one or more of the four motors (Root, Sacral, Solar Plexus, Heart) to the Throat center. This is a Design “to do.”

Split definitions can have more than one type at the same time.

Uranus Opposition
At about age 40, a life shifts from the themes of the South Nodes to the themes of the North Nodes, from inhaling to exhaling. It is often experienced as a time of change and even the “midlife crisis.”

These details become more important after you're very familiar with your own chart but are introduced so you can reference why your chart summary is the way it is, You don't need to get it all at once. Start with doing or waiting! Sounds easy but it's profound.

Author's Bio: 

Zeno has a design to wait and this has been a very important lesson to stop trying to do. Makes so much difference when you realize your own mode (either to do or to wait). www.humandesignsystem.com

Additional Resources on Human Design can be found at:

Website Directory for Human Design
Articles on Human Design
Products for Human Design
Discussion Board
Zeno Dickson, The Official Guide of Human Design