Which two imaginary lines mark the tropical climate regions?

The Tropic of Cancer is at approximately 23 degrees 30 minutes N latitude and marks the point on the Earth's surface where the Sun is directly overhead at the northern Summer Solstice. It also marks the northernmost point of the Tropic Zone. The Tropic of Capricorn is at approximately 23 degrees 30 minutes S latitude and marks the point on the Earth's surface where the Sun is directly overhead at the southern Summer Solstice. It also marks the southernmost point of the Tropic Zone.