The zodiac wheel, aka the horoscope, contains 12 houses. Each house represents an area of life of a person. The constellation of the planets are blueprinted from the moment of birth, from the first breath. Your path in life. Your horoscope is only accurate when your birthdate, time & place of birth is known. 

When you are born, your sun is in a particular sign as you know. But what most people do not know is that your moon & ascendant are also in a particular sign and these 3 (aka 'the big 3' ; Sun: your present, Moon: your past, Rising: your future) determine your personality. So your sun sign represents your present state, your moon signifies your memories from the past and your rising sign is where you are headed towards, where you (sub)consciously are growing into. When your ascendant is i.e. in Sagittarius, it means that your 1st house is ruled by the energy of Sagittarius and Jupiter is the lord of that sign. In your chart you look at which placement (house & sign) Jupiter is, in my case it's in Scorpio. The 1st house has always the undercurrent energy of Aries: 'the self'. 

So what you project outside into the world (the horizon), where you are growing, is that you combine all these energies in 1, in my case that would mean: I am (Aries) interacting (ascendant) like a curious, adventurous (Sagittarius) person and grow (Jupiter) from diving deep into the unseen occult & taboo truth (Scorpio). My ascendant energy contains fire & water; fire is the inspiration from above and water is the flued of emotions (and water flows anywhere easily through) from the underground (below). 

The houses from the ascendant (1st house) till the 7th house entails the energy (so below) of what resides inside of us, the energy what we inherited from our parents, our soul experiences, our mother (moon) and father (sun) energy (the self, the worth, the thinking, the house, the children & play, the day to day things); the energy from the 7th- 12th house (as above) is the extraverted energy (the relationships, the contracts, the debts, the knowledge, the status, the friends, the institutions & secrets). That's the circle of life, the circle of karma, the waves of infinity: what goes around (above), comes around (below). What you experience in the outer world, has an impact on your inner world. From dust (behind the horizon, 12th house, the hidden, that what you take from previous life's into this one, that what you hide from the world), till dawn (the horizon, the ascendant, that what you show to the world).