1. Syntax: The key difference between AWK and Lua lies in their syntax. AWK uses a pattern-action paradigm where patterns define conditions to trigger actions, while Lua follows a more traditional imperative approach with functions and control structures.
2. Typing: AWK is dynamically typed, meaning variables don't have a specified type until runtime, whereas Lua is statically typed, requiring variable types to be declared during compilation.
3. Usage: AWK is primarily used for text processing, especially in Unix environments, with built-in functions for file input/output and regular expressions. On the other hand, Lua is a general-purpose scripting language suitable for a wide range of applications, from game development to embedded systems.
4. Extensibility: Lua is known for its extensibility, with a robust C API allowing for seamless integration with existing codebases, whereas AWK lacks the same level of flexibility in terms of extending or embedding functionalities.
5. Scoping: AWK has a global scope by default, with limited support for local variables and functions, whereas Lua provides better scoping mechanisms with global, local, and upvalues for better code organization and encapsulation.
6. Object Orientation: Lua supports object-oriented programming paradigms, such as classes and inheritance, making it more suitable for complex software design, while AWK lacks direct support for OOP concepts.

In Summary, the key differences between AWK and Lua lie in their syntax, typing, usage, extensibility, scoping, and object orientation.