A birth chart is only one way people use Western astrology. Traditionally, astrologers also drew charts for questions, beginnings, and communities. The four branch names tell you what kind of question a chart is meant to address.
Natal is about a birth; mundane is about a community
Natal astrology begins with a person's birth date, time, and place. It looks at the chart for that moment. Mundane astrology looks at collective subjects, such as a city or country. The name doesn't mean an ordinary or boring chart.
Horary starts with a question; electional starts with a plan
In horary astrology, an astrologer draws a chart for the time a specific question is asked. In electional astrology, an astrologer compares possible times to start an activity, such as opening a shop. These are descriptions of traditional methods, not promises that a chart can settle a question or make a plan succeed.
Choose the name by the subject
Ask what the chart is about: a person’s birth, a specific question, a planned start, or a matter affecting a community. That clue usually tells you which branch you are reading about. You do not need to learn every method to understand the labels.
A few common questions
Is horary astrology the same as a birth-chart reading?
No. A natal chart is set for a person's birth. A horary chart is set for the time a particular question is asked.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.