The ‘houses’ refer to divisions of the local sky into 12 parts. They are used to make distinctions about different parts of the life of a person (or question/event).
Beyond this basic premise, there’s a bewildering array of different ways to chop the sky and read its meaning.
Many people seem to be confused about how to read houses. Also, I feel that modern house drawing conventions can be misleading.
Here’s some of my recent thinking on the subject.