Every birth chart is a circle, which is, of course, made up of 360 degrees. Each planet occupies a specific degree of the circle. The angles the planets form to one another in the chart—the aspects—describe the relationship between those planets.
In Astrology, the square and opposition indicate hardships, while trines are seen as blessings. Yet, without the challenging aspects, the so-called easy aspects have little value.
When interpreting aspects, the Astrologer must be careful to note which kinds of aspects are most prominent.
For instance, it's necessary to consider the "orb," or how close the aspect is to its exact degree. Although it is traditional to use an orb of 8°-10° for the aspects listed below, the smaller the orb—the more exact the angle—the more significant the aspect.
One of the keynotes of Modern Astrology is the belief that we need challenge in our lives in order to learn, the goal being to cultivate deeper understanding & awareness of our easy aspects (talents) to successfully overcome the hard aspects (challenges). This process of self-awareness is what leads the individual to true growth and feelings of accomplishment.
Here I’ll outline what most Astrologers consider to be the “major,” or most relevant, aspects in interpreting a chart.