The 7th house of your birth chart is all about partnerships. Often, this refers to romantic partnerships, but it can certainly speak to working relationships, too -- but no matter what, this house is about one-on-one relationships. The sign and planets in the 7th house of your birth chart impact the way you look and act in relationships. For example: A person with Aries in the 7th house of their chart would approach relationships from a more independent self-satisfying standpoint, whereas Cancer in the 7th house would be more about gaining security from a relationship and nurturing the other person.
In Astrology (but not necessarily in your own birth chart), the 7th house is associated with balanced, harmonious Libra, the great equalizer, and the icon of an equal partnership. The 7th house is also ruled by the love planet Venus, hence the 7th house's connection with, mostly, romantic partnerships.