What are Aspects in Astrology? How do I find out the aspects in my Birth Chart?

This is going to be a quick and simple introduction to the astrological aspects, simply to lay the foundation of basic knowledge, because I want to start writing about the different aspects, so I really feel like the most important questions on the topic should be answered :)
Let's start!

Aspects in Astrology

An aspect is a specific angle between a celestial body and another one or an axis (Ascendent, Descendent, Midheaven, Immun Coeli).
It is the relative geometric relationship between specific points in the sky, so to say.
But that sounds boring so lets call it "in which specific ways the parts of the horoscope relate to each other".
These aspects, these specific angles, show the relationships between these parts in the horoscope.

The Major Aspects Are:

Aspects are also categorized as "harmonic" and "inharmonic", depending on whether they make the relationship between the planets and points involved easy and flowing (harmonic) or hard and challenging (inharmonic).
However, you should realize that harmonic isn't solely good and that inharmonic isn't solely bad.
Harmonic aspects can also show that there is no real potential for growth, because there is no challenge, no friction - like is the case with inharmonic aspects.

Harmonic aspetcs: Trine, sextile
Inharmonic aspects: square, opposition
Neutral /depending on the planets involved: Conjunction

What are the Aspects in my Chart?

Birth Charts usually come with an aspect table. It's pretty easy to see which aspects the celestial bodies and axes create, if you can read the aspect symbols, that are shown in the table above!!
It's also important to know the symbols for the planets, of course.

If you work with an aspect table or grid, you simply look at the column of one planet and the row of another planet and you'll be able to tell which aspect they create (if they do)

What are Orbs?

It is very rare that two planets are ever in an exact aspect to each other, that they, for example create a perfect 90° angle to each other.

In astrology, the orb is how much an angle made by two points differs from the exactness of an aspect. (wikipedia)

So, the angle between two planets, could, for example, be 87° or 92° but still be considered a square aspect!
The respective orbs are as follows;

Conjunction

A conjunction is an angle of 0°, this means that the two planets or points involved were in one line as seen from the earth. Their energies merge together, they are blended. One planetary theme is involuntarily linked with the other, they become an inseperable unit. Expressing one psychological aspect without the other is almost impossible, because they are linked in and intricate way. That is why the conjunction can be both inharmonic or harmonic, depending on the planets involved; some work well together, others - not so much.

Opposition

An opposition is an angle of 180°, which indicates that the points forming this aspect are facing each other, opposite of each other. Although this does create a conflict, a constant back and forth of opposites that seem to not go together, the scale that dips from one side to another can eventually find a balance. This is still a big challenge, though, and that's why it is usually considered a inharmonic aspect.

Square

A square is an angle of 90° and considered inharmonic. Planets that form this aspect together are usually at complete cross-purpose and their themes are really hard to combine, because they want completely different things and frequently butt heads. It's like two cars driving into a cross-street in a 90° angle to each other and then crashing because they didn't see each other. These planets themes are very hard to combine and they usually show as painful experiences and feelings.

Trine

A trine is an angle of 120° that usually happens between signs of the same element. This indicates things that come very naturally and easily, they're a talent you're born with. The planets energies flow harmoniously together and the benefits can be used easily. It comes so naturally, that people often aren't aware of these strengths and talents and that they aren't used as much and as constructively as they could be.

Sextile

A sextile is an angle of 60° that usually occurs between two planets of the same polarity but differrent elements. This means that there is creative and positive potential slumbering that can either be used or not. Its a harmonious aspect like the trine, but usually less strong and not as obvious and evident.

How to find your strongest aspect