What's a serverless function, and how does it compare to backend code deployed and executed on a server? Use no more than four sentences to explain.

Previous conversation I had with ChatGPT:
When Yew.rs is compiled to WebAssembly, how is that run? What is the file extension?
When Yew.rs is compiled to WebAssembly, the resulting code can be run within a web browser. The compiled file extension of WebAssembly is typically “.wasm”. However, when using Yew.rs, the WebAssembly module is usually bundled with JavaScript and served as a “.js” file. This JavaScript file usually contains the glue code to interact with the WebAssembly module and provide a more ergonomic interface for interaction with the web browser’s APIs.
When you say “served as a ‘.js’ file”, do you mean served with both a .js and .wasm file where the .js file is the starting point or is the .wasm somehow inside the .js?
When Yew.rs is compiled to WebAssembly, typically both a “.js” and a “.wasm” file are generated. The “.wasm” file contains the compiled WebAssembly code, while the “.js” file serves as a wrapper or glue code to interact with the WebAssembly module.

In this typical setup, the “.js” file acts as the starting point and is responsible for loading and initializing the WebAssembly module. It typically contains the necessary functions to instantiate the WebAssembly module, perform memory and resource management, and provide a higher-level API for interaction with the module. The “.wasm” file is referenced and loaded by the “.js” file during runtime.

The “.js” file will interact with the WebAssembly module by importing and exporting functions, and it may also handle communication between the WebAssembly module and the web browser’s JavaScript APIs.

So, in summary, the WebAssembly module is packaged as a “.wasm” file, and it is loaded and initialized by a corresponding “.js” file acting as a wrapper to provide an interface for the web browser.
Imagine all the aforementioned is for the frontend and that the backend is native Rust code. How does this change things?
If the backend is implemented as native Rust code, it would typically be compiled into a binary executable specific to the target platform (e.g., Linux, Windows, macOS). Unlike the frontend, which utilizes WebAssembly and JavaScript for running in web browsers, the backend code does not require any additional files or wrappers specific to the Web.

The compiled Rust executable can be run as a standalone server or service, independent of the web browser. It can listen on specific ports, communicate with databases or external services, and respond to requests from clients. The backend code can be deployed and executed on a server or deployed as a serverless function.

Both the frontend and backend can communicate with each other through various mechanisms such as RESTful APIs, web sockets, or GraphQL. The frontend can make HTTP requests to the backend for data retrieval or update, while the backend can send data and updates to the frontend as necessary.

In summary, the frontend and backend components may have different deployment strategies and runtime environments. The frontend relies on WebAssembly and JavaScript for the web browser, while the backend is compiled as a native executable, which can be deployed and run independently on servers or services. The interaction between the frontend and backend can be facilitated through various communication protocols.