House
One of twelve divisions of the sky, cut from your birth time and place, each covering an area of life.
Signs answer "in what manner"; houses answer "about what". The same Venus in the second house and in the seventh describes two quite different parts of a life.
The twelve are not equal in size unless you use the equal-house system. Placidus, the common default, divides by time, which at high latitudes stretches some houses very wide and squeezes others — a known property of the method, not an error.
Houses depend entirely on the birth time. If the time is shaky, so are the houses, and it's better to work from planets and aspects alone.