Before exploring what WebAssembly is, the advantages, and how it is useful, here is another functionality that is closely associated with the WebAssembly, called LLVM. WebAssembly (abbreviated Wasm) and LLVM together are responsible for the binary instruction format for the stack-based virtual machines.
Below is a visual representation of the WebAssembly and its operation.
WebAssembly also overcomes the challenges posed by Java Applet and Flash from the past like poor integration with the browsers, additional run-time and plug in requirements, and security concerns.
Here is an illustration of the WebAssembly flow, an excerpt from the above video.
The creation of a .wasm file is an interesting subject in itself, despite the existence of differences in terms of Target Platforms, Instruction Set Architecture and Operating Systems.
Thus, the visible piece of the Rust ecosystem, to a programmer, in the whole process is the rust compiler.
The process of creating a machine-understandable code is a two-phase activity:
Compilers like Rust/Swift/C++/Kotlin and many others perform the frontend job of enforcing their language-specific rules on the source code to produce an LLVM Intermediate Representation. The LLVM backend takes this IR to produce a machine code that is understandable by the target. Thus, your compiled code, whether it is an executable or a shared library, becomes language-agnostic when it is represented in the Intermediate Representation.
Security is the most important vector for any web application. The main storage of a WebAssembly is a large array of bytes called linear memory. The linear memory is disjoint from the code space and the execution stack. This insulates the compiled program from corrupting the execution environment by jumping to arbitrary locations to open gates for compromising security.
WebAssembly helps to move portions of the heavy-duty operations that are being performed at the Server-Side to the Browser. This will help in reducing the total cost of ownership by freeing up the server resources and in reducing I/O overheads.