Code optimization is the process of improving the performance of a program by reducing its resource consumption. In the case of JavaScript, it means making your code run faster and use less memory.

1. Minification: This involves removing unnecessary characters from your code to reduce the file size. This can be done using tools like UglifyJS and Closure Compiler.

2. Concatenation: By concatenating multiple JavaScript files into one, you can reduce the number of HTTP requests required to load your page, which can improve performance.

3. Caching: Storing frequently accessed data in memory can help reduce the amount of time it takes to retrieve it later. This can be achieved using techniques like memoization or caching libraries like Redis.

4. Avoiding unnecessary work: By reducing the amount of work your code is doing, you can improve its performance. This can be achieved by using techniques like lazy loading or only executing code when needed.

5. Profiling and benchmarking: Measuring the performance of your code is crucial to identifying areas that need optimization. Tools like Chrome DevTools or Firebug can help you analyze the performance of your JavaScript code.

6. Hardware acceleration: Certain actions can be performed more efficiently using specialized hardware like graphics cards or Digital Signal Processors (DSPs). By offloading some processing work to these devices, you can improve the performance of your JavaScript code.

By applying these and other optimization techniques, you can improve the performance of your JavaScript code and provide a better user experience for your users.