Astrology Basics: Modes, Aspects, Symbols, Meanings in Astrology Charts

Aries         Capricorn

Cancer               Libra

Initiating Action.
Reaction.
Getting Things Going.
Interested in crisis, activity, and what is going on.
Initiators.
Start of something.
All Cardinal signs correspond to the beginning of the Seasons.
Aries = Spring
Cancer = Summer
Libra = Fall or Autumn
Capricorn = Winter
Focus is on Identity.
Action is motivated, inspired and begun.
Commencing, Originating.
These signs are self motivated through:
Creative Impulses - Aires
Emotions - Cancer
Relationships - Libra
Urge for success-Capricorn

Taurus       Aquarius

 Leo                 Scorpio

Manifests Purpose & Will.
Getting Things Done.
Interested in values & ideas.
Consolidating.
Determined.
Stabilizers of Universe.
Putting down roots - settling.
Maintaining.
Preserving.
Sustaining.
Predictability.
Consistent, Persistent.
Focus is on Securing.
Action is intensified, sustained, and supported.
Sustaining what has already been created.
 Concentrating, Focusing.
These signs express their qualities through:
Personal resources-Taurus
Personality - Leo
Will Power - Scorpio
Aspirations - Aquarius

Gemini           Pisces

 Virgo       Sagittarius

Adapting to Change.
Wisdom.
Alternating, Flexible.
Interested in people and relationships.
Transformation.
Correspond to the time of one season giving way to another. Preparation for the next cycle.
Knowledge & Consciousness.
Focus is on Learning and completion of the cycles.
What has been created is altered, transformed, enhanced, rearranged, or dissolved so it can operate at a higher level. 
Adapting, Dispersing.
These signs express, connect and communicate through:
Ideas - Gemini
Practical Skills - Virgo
Knowledge - Sagittarius
Feelings - Pisces

How the Modes Create Aspects In Your Chart
Using the diagrams,  above you can see which planets have more difficulty relating. 
These diagrams make squares  (obstacles) and opposition  (conflicts) visible.

Planets in Signs on the Diagonals are in Opposition.
(Ex:  Aries opposes Libra, Leo opposes Aquarius, Pisces Opposes Virgo, etc.)

Planets in Signs at Right angles to each other are Square.
(Ex:  Cancer squares Libra, Taurus squares Leo, Virgo squares Gemini, etc.)

Planets and Signs in Elements (See Signs) of the same nature create Trines. 
(Ex:  Planets in two fires signs are Trine, Planets in two earth signs are Trine, etc.)
Trines  generally indicate ease or harmony

Blending the power of  both energies.
Powerful Aspect.
Two (or more) Planets or Chart Points at same position on the chart by sign and degree.
Concentration of two different energies.
Potential for strengthening of the two unique energies to create a new strong energy.
Beginning of a new cycle involving the two planets.
Same degree of sign.

Conflict between opposing energies.
Calls for awareness.
Learning cooperation and compromise of the energies is the task.
Difficult tensions.
Need to integrate.
The flow of energy or relating is obstinate and challenging.
Opposing forces that must be reconciled.
Awareness allows consciousness to expand and fosters growth.
Opposite each other
by 180 degrees.

Aspect of confrontation, challenge, internal tension,  strength.
Indicates difficulty, but also excitement.
Uses internal conflict to bring about change.
At cross purposes.
Inharmonious.
Antagonistic energies that precipitate rapid changes.
How we achieve things and get things done.
Obstacles.
This is a 90 degree angle between points

Trine

Aspect of Harmony
Protective influence
Cooperation.
Creativity.
Growth. Vision.
Flow and Ease.
Use of energies effortlessly to express creativity.
Creative Potential.
Planets in Trine are usually in the same element (fire, air, water, or earth)
Indicates inborn talents and gifts.
This occurs when planets are 120 degrees apart.

Aspect of Opportunity to be creative or productive.
Possibilities.
Requires effort but if actualized can bring much to fruition.
Needs practical application of one's skill and information.
Balance.
 Harmony.
Rest.
Planets are usually of  same polarity (yin  yang), but of different elements.
Occurs when planets are 60 degrees apart

Aspect requiring courage and will to adjust attitudes and resolve conflict.
Contradiction.
Paradox.
Potential for focus, transformation, maturity and clarity.
Real vs. Ideal.
Planets in these signs have nothing in common.
Strain and separation.
Requires some sort of adjustment.
Occurs with 150 degrees separates planets or bodies.

Occurs when planet appears to move backwards.  
Energy of the planet is turned inward.
Planets operate differently than the normal.
Sometimes indicates delay or false starts and also means another opportunity for relearning of growth cycles perhaps not completed on earlier orbits and transits.
Will be marked by the symbol above on charts.