WebAssembly (or WASM) is a low-level, binary instruction format for executable code on the web. It is designed as a portable target for compilation of high-level languages like C/C++/Rust, enabling deployment on the web for client and server applications. WebAssembly aims to execute at near-native speed by taking advantage of common hardware capabilities available on a wide range of platforms. It is also designed to be memory-safe, with built-in support for detecting and handling memory access errors. WebAssembly can be used in conjunction with JavaScript, allowing developers to leverage both languages in their applications.