Astrologers consider that your Sun sign describes your core personality ... and many will say it is the most important sign you have, although that's not entirely correct. The Moon sign and the Ascendant sign are just as important -- although they are impossible to accurately determine unless an astrologer actually casts your horoscope and looks at the information it contains.
The Sun when well-supported brings willpower, pride, the desire for personal glory, and the drive to "shine" in the eyes of the world. It prompts actions that have impact and the show you are important. The focus is on being recognized ... for all the things you are. A well-supported Sun in a horoscope has other planets that form helpful angles with its position. These angles are known as aspects, and the benevolent ones -- the conjunctions, sextiles, and trines -- show planets aligned with the Sun's interests in ways that are sympathetic, cooperative, supportive, or working from a foundation of similar values.
Planets that form conjunctions, sextiles, or trines with The Sun bring their qualities and strengths, skills, abilities, and interests to support those of the Sun in the way it expresses itself, the work it performs, and the results it produces. The Sun, of course, reciprocates with this "partner planet," lending vitality, charisma, and confidence to what it represents in a person's character ... and the agenda it has set out to perform.
If The Sun in your Natal Chart has planets that form conjunctions, sextiles, or trines to support it ... your personality has added "ego strength." Your character has help expressing itself well, and your natural talents have ready-made channels for development and areas of life where they can display themselves well.
The Sun when stressed is an energy that degrades into an atmosphere or character that is arrogant, vain, egotistical, self-centered, petty, and pompous. The recognition you seek is hindered somehow ... and you feel slighted, discounted, mistreated, insulted. (And you respond to that just as one might expect! Badly.)
Planets that form squares or oppositions with The Sun apply their qualities and strengths, skills, abilities, and interests in ways that interfere with, hinder, irritate, or otherwise stress the Sun and its ability to express itself, do the work it wants to do, achieve its ambitions, or gain the results it desires.
If The Sun in your Natal Chart has planets that form squares or oppositions with it, your personality feels hindered, limited, divided, "torn in different directions," forced to time-share your resources, or in some cases chronically blocked and frustrated ... unable to express yourself well, impeded in gaining your desires, unable to achieve your ambitions easily -- if at all, and deprived -- or at least delayed -- in gathering the respect and authority that marks you as "someone important" in the family, social, and business circles where you want others to value you and your contributions.
These descriptions hold true whether the helping or hindering planet is also contained in the Natal Chart (and therefore is constantly in its positive or negative position relative to The Sun) or whether it is transiting in the sky (and therefore is only temporarily involved in the expressions of The Sun, for better or worse.)
The horoscope is divided into twelve different sections called houses ... which represent the twelve major divisions of life interest and experience. The house in your Natal Chart which contains the Sun shows the area of life and the kind of concerns where you want attention -- and where you pay a lot of attention, where you want to be noticed, where you want to be considered essential and influential. It is the most important area of life to you. It's where you want to be proud of yourself and what you do. It describes what makes you feel alive ... and what you consider your real reason for living.
Information based on your Sun sign alone is "better than nothing," but it is also seriously incomplete. Forecasts based on your Sun sign will tell you what is happening with regard to your ego, your self-image, and your personal development out in the world. But that's not all you are ... not by a long shot.