There are eight planets and two luminaries in each chart. We call the Sun and Moon luminaries or lights, as they are technically not planets. Each planet/luminary has its own unique meaning and energy. How that energy is expressed will depend upon the sign the planet is in, the house it is in, and the aspects it gives or receives.
Here are some basic meanings of each planet.
Sun.
The Sun represents your basic personality, who and what you are, what your
purpose is here in this lifetime, your basic health and strength, your
conscious mind, your ego, and your adult self.
Moon.
The Moon represents your subconscious mind, your childhood, your Mother,
your relationships with women, your nurturing side, your intuitive self,
and your emotions and how they are expressed. It also represents
instinctual needs.
Mercury.
Mercury represents your mind, your intellect, how you communicate, how
well you do in school, your learning style, your speech patterns, and how
you think.
Venus.
Venus represents how you love, what you seek in love, your appreciation
for the arts, your financial possibilities, your feminine side, and how
you relax.
Mars.
Mars represents your masculine side, your energy level, how you express
your energy, your temperament, your ability to take direct action, and
your sexuality.
Jupiter.
Jupiter represents your expansive capabilities, your ability to draw luck
to you, and your religious beliefs and interests.
Saturn.
Saturn represents your fears, your struggles, your difficulties, your ability
to be practical, your ability to organize, and your business sense.
Uranus.
Uranus represents your eccentric side, your connection with humanity at
large, your ability to be inventive, your relationship with electronics
and computers, and your capacity for brilliance and insight.
Neptune.
Neptune represents your longing to be connected to the whole, your deep
inner spirituality (as opposed to organized religion), whether or not you
overindulge in chemicals, your need to merge with something outside yourself,
your compassion on a higher level, and your higher self.
Pluto.
Pluto represents your capacity for rebirth and regeneration, your ability
to transform things, your interest in all things hidden or occult, how
you approach death and sexuality, your understanding of the human psyche,
and your ability to radically disrupt or alter your life.