ELI5: Imagine you want to run a heavy, powerful 3D video game engine inside a standard web browser or a lightweight desktop app, without making it slow or unsafe.

JavaScript alone can't handle that kind of heavy lifting efficiently. That’s where Wasm comes in. It lets you run high-performance native code (like C++) at near-native speed safely in the sandbox.

For example, I'm currently using Wasm to run a complex 3D geometry engine (Manifold) inside a lightweight CAD app (Nasscad). It gives you web flexibility with desktop power.