Bundlers and task runners are essential tools in modern web development, streamlining the process of building and managing complex applications. Bundlers, like Webpack, are designed to take various types of assets—such as JavaScript, CSS, and images—and bundle them into a few output files. This helps to optimize load times and manage dependencies efficiently. Webpack, for example, allows developers to define entry points for their application, specify output locations, and configure how different types of files should be processed and transformed before being included in the final bundle.

On the other hand, task runners like Gulp automate repetitive tasks in the development workflow. These tasks might include compiling code, minifying files, or reloading the browser upon changes. Gulp uses a code-over-configuration approach, where developers write JavaScript code to define tasks and their sequence. This makes it highly flexible and powerful for automating complex workflows. While Webpack focuses on bundling and optimizing assets, Gulp is more about streamlining and automating the build process, making both tools complementary in modern web development setups.