what is that one thing in chandrayaan 3 and not in chandrayaan 2

The one standout thing in Chandrayaan-3 that Chandrayaan-2 did not have is the SHAPE payload on the propulsion module, which studies Earth’s spectral and polarimetric data from lunar orbit. Chandrayaan-3 also carried a redesigned lander with several upgrades, but if you mean a single unique feature, SHAPE is the clearest answer.

Quick Scoop

Chandrayaan-2 had an orbiter, lander, and rover , while Chandrayaan-3 was built with a lander, rover, and propulsion module using the existing Chandrayaan-2 orbiter for communication support.

What’s Different

• SHAPE payload: present in Chandrayaan-3, not in Chandrayaan-2. It is used to study Earth from lunar orbit.

• No new orbiter in Chandrayaan-3: unlike Chandrayaan-2, Chandrayaan-3 did not add a separate orbiter of its own.

• Improved lander design: Chandrayaan-3’s lander was redesigned for a safer soft landing, with stronger legs, extra fuel, and better sensors.

One-line answer

If you want just one thing , say: the SHAPE payload.