The WebAssembly.Instance object is the instantiated WebAssembly module, which means you can call exported WebAssembly functions from it. Calling instantiate() or instantiateStreaming() returns a Promise that resolves with an object containing an instance. You call WebAssembly functions by referencing the name of the function on the instance's export property. For example, if a module contained an exported function named sayHello(), you'd call the function using instance.exports.sayHello().