>>40577986
Aspects are the shapes formed from the position of the signs on the Zodiac Wheel. There's four Triplicities (elements) that are grouped as Fire, Air, Water and Earth.

Each of those signs has a Nature and Quality, along with a Gender. These reflect the nature of the planets that rule them, and tell you about what that sign represents.

Fire = Hot and Dry
Air = Hot and Wet
Water = Cold and Wet
Earth = Cold and Dry

Masculine = active and likes day time
Feminine = passive and likes night time

Picrel shows the triangle each of these element clusters (Triplicities) form. Because each of the elements share the same Nature and Quality, in addition to a Gender, they get along very well. Imagine having a friend that matches your interests, energy level, hobbies and views closely, that's similar to a Trine because so much is shared in common.

Now take a Square. A Square aspect is like a member of your friend group who you don't get along with but don't hate, because you both have little in common.

In picrel, if you make a triangle from Aries to Leo, it makes a trine. If you go back one sign to Cancer, it forms a square shape. Cancer is a feminine sign that's cold and wet. Aries is a masculine fire sign that's hot and dry. They don't share anything in common except modality (they're both cardinal signs) so they don't get along.