The climatic zones are classified on the basis of rainfall. This means that the amount of precipitation in a particular area is used to determine its climatic zone. Let's break down the explanation into headings and HTML bullet points for better understanding:

Factors influencing climatic zones:

1. Distance from the equator:
- The distance from the equator does have an impact on climate, but it is not the primary factor in classifying climatic zones.
- The closer an area is to the equator, the hotter it tends to be, but this does not determine the climatic zone.

2. Elevation:
- Elevation, or the height above sea level, can also influence climate.
- Higher elevations generally have cooler temperatures due to a decrease in air pressure and the associated cooling effect.
- However, elevation alone is not sufficient to classify climatic zones.

3. Distance from the sea:
- The distance from the sea can have a moderating effect on climate.
- Coastal areas tend to have milder and more moderate temperatures compared to inland areas.
- This is because the sea acts as a heat sink, absorbing and releasing heat more slowly than land.
- However, distance from the sea is not the primary determinant of climatic zones.

Classification based on rainfall:

- The primary factor used to classify climatic zones is rainfall.
- The amount and distribution of rainfall in an area play a crucial role in determining its climate.
- Different climatic zones are defined based on variations in rainfall patterns, such as the amount of rainfall received annually or seasonally.
- The five major climatic zones based on rainfall are tropical, dry, temperate, continental, and polar.
- These zones are further divided into subcategories based on specific rainfall characteristics.

Conclusion:

In conclusion, the classification of climatic zones is primarily based on rainfall. While factors such as distance from the equator, elevation, and distance from the sea can influence climate, they are not the main criteria for determining climatic zones. By focusing on rainfall patterns and variations, scientists and meteorologists can accurately classify and study different climatic zones around the world.