1. Inert Atmosphere: Helium's inert nature makes it ideal for creating an atmosphere where reactive substances can be handled safely. This is utilized in:

* Welding and cutting: Helium is used as a shielding gas in welding and cutting processes to prevent oxidation and contamination of the molten metal.

* Growing crystals: In crystal growth, helium provides a controlled environment to prevent impurities from contaminating the growing crystal.

* Arc lamps: Helium is used to fill arc lamps, providing an inert environment for the electrical discharge.

2. Lifting Gas: Helium is much lighter than air, making it a suitable lifting gas for:

* Balloons and airships: Helium is used to fill balloons and airships, providing lift and enabling them to float.

* Scientific instruments: Helium is used to lift weather balloons, research balloons, and other scientific instruments to high altitudes.

While these are the two main functions, helium also has other applications, including:

* Medical imaging: Helium-3 is used in magnetic resonance imaging (MRI) to enhance the clarity of images.

* Refrigeration: Helium is used as a cryogenic refrigerant to achieve extremely low temperatures.

* Leak detection: Helium is used to detect leaks in high-pressure systems.

Therefore, while helium's inert nature and its ability to lift are its primary functions, it plays a significant role in various other fields.