Do you have 4 or more planets in the same house? Your chart will show you if you have a few planets in a house. The chart above is of Joe Kennedy, with a stellium in the 12th house. President John F Kennedy had a stellium in the 8th house. If you have 4 or more in one house then your challenges are more than most in that area of your life or will be more exciting and super-charged than most in that area.

The 1st house, referred to as the Ascendant: the Self, demeanour, and vitality.
The 2nd house: money earned and material goods.
The 3rd house: immediate surroundings, siblings, short trips, and studies.
The 4th house, referred to as the Imum Coeli: family, home, origins, heredity, and the father.
The 5th house: love matters, pleasure, leisure, children, and creations.
The 6th house: everyday life, daily work and colleagues, lower-ranking co-workers, and health.
The 7th house, referred to as the Descendant: unions, marriage, other people, associations, and contracts.
The 8th house: passions and crises, transformations, death, financial investments, and sexuality.
The 9th house: travels, abstract and higher concepts, spirituality, and foreign matters.
The 10th house, referred to as the Midheaven: social success, professional destiny, and the mother.
The 11th house: friends, collective projects, supports and protections in life.
The 12th house: enemies, difficulties, solitude, hidden ordeals, and secrets.

If you would like to see your birth chart, I use astro.com for free astrology stuff: http://www.astro.com

This is an excellent in-depth article explaining what stelliums are, how they pertain to each house and how to balance things out if you are faced with challenges from your stellium: http://www.lynnkoiner.com/astrology-articles/the-stellium-4-or-more-planets-in-the-same-house