Answer

In Jain practice, Teevihār / Teenthui and Chauvihār / Charthui refer to different levels of food-and-water restrictions, especially observed during fasting, evening discipline, or certain vows.

• Teevihār / Teenthui: Giving up three types of intake, but water may be allowed under proper rules.
• Chauvihār / Charthui: Giving up all four types of intake, including water.

Explanation

In Jain tradition, food and drink are commonly grouped into four categories:

• Ashan – solid food
• Pān – drink/water
• Khādim – chewable/eatable items like fruits, dry fruits, etc.
• Swādim – taste-based items, mouth-fresheners, etc.

So:

• Teevihār means renouncing three of these categories, while usually keeping permission for boiled water within the allowed time and rules.
• Chauvihār means renouncing all four categories, so even water is not taken.

Spiritual Understanding

• Teevihār is a disciplined form of restraint, but slightly lighter because water may be permitted.
• Chauvihār is stricter and considered a higher level of renunciation because it includes complete restraint from food and water.

Takeaway

Teevihār = no food items, but water may be allowed.
Chauvihār = no food and no water.