Kausagg (काउसग / कायोत्सर्ग) in Jainism means “letting go of the body”.

1. Meaning

• Word comes from: kaya (body) + utsarga (giving up / letting go).
• It means: mentally leaving attachment to the body and focusing on the pure soul (आत्मा).

2. How it is done (posture) Usually done standing, sometimes sitting:

• Stand straight, feet steady and slightly apart.
• Hands relaxed by the side (or slightly away from the body).
• Body completely still.
• Eyes downcast or gently closed.
• Breathe naturally.
• Mind focused on:

- the soul, or - reciting mantras/sutras like Namokar Mantra, Logassa etc.

3. Purpose / Benefit

• To practice detachment from the body.
• To stop new karmas and shed old karmas.
• To develop equanimity (समता), peace, and inner purity.

4. Where Kausagg is used

• In Samayik
• In Pratikraman
• In Chaitya‑vandan

Both Śvetāmbara and Digambara traditions do this, though the exact sutras recited may differ.

You can read a simple explanation here