Answer

Here is the simple difference:

• Chovihar: No food, no water, and nothing taken by mouth after sunset.
• Tivihar: No food and no water after sunset, but some traditions allow necessary medicine.
• Ekasan: Eating only one meal in the whole day, in one sitting, usually before sunset.

Explanation

You can think of them like this:

• Chovihar is about strict night restraint.
• Tivihar is also a night restriction, but slightly less strict than chovihar.
• Ekasan is about how many times you eat in a day, not mainly about sunset.

So:

• Chovihar/Tivihar = rules about after sunset
• Ekasan = rule about one meal in a day

Spiritual Understanding

These practices help Jain followers with:

• Self-discipline
• Less attachment to food
• Carefulness and restraint
• Purification of conduct

In Jain Dharma, such practices are not just fasting rules; they are ways to reduce desires and live with more awareness and non-violence.

Takeaway

In one line:

• Chovihar = strict no food/water after sunset
• Tivihar = slightly less strict night restraint
• Ekasan = one meal in the day

If you want, I can also explain these in a very short comparison table.