Apache Maven and Yarn are both widely used build management and dependency management tools in the software development industry. While they serve similar purposes, there are key differences between them that set them apart.

1. Dependency Management: Apache Maven focuses on centralized dependency management using a Project Object Model (POM) that defines all the dependencies and their versions in a single file. It allows for transitive dependency resolution, ensuring that all required dependencies are included. In contrast, Yarn is primarily a package manager for JavaScript and manages dependencies at the package level. It creates a lock file that ensures consistent package versions across different development environments.

2. Language and Ecosystem: Maven is primarily designed for Java projects and works seamlessly with the Java ecosystem. It provides extensive support for building, testing, and deploying Java applications. Additionally, it has a large repository of plugins and libraries specifically for Java development. On the other hand, Yarn is designed for JavaScript projects and is commonly used in conjunction with Node.js. It leverages the npm registry to manage JavaScript packages and is well-integrated with the JavaScript ecosystem.

3. Build Configuration: Maven uses an XML-based configuration format, where the build process is defined in the POM file. This allows developers to easily customize the build lifecycle and specify various phases and goals. Yarn, on the other hand, uses a declarative configuration format with a JSON file called "package.json". The build configuration is defined using scripts, allowing developers to define custom scripts for different build tasks.

4. Performance and Scalability: Apache Maven has been around for a longer time and has a mature ecosystem. It can handle large-scale projects with a large number of dependencies and plugins. However, the build process can sometimes be slower due to its centralized approach and XML configuration. Yarn, being more focused on JavaScript development, is optimized for performance and is known for its faster dependency resolution and installation. It is specifically designed to handle large-scale JavaScript projects efficiently.

5. Integration with Build Systems: Maven is tightly integrated with the Apache Ant build system. It can inherit and extend Ant tasks for a more flexible build environment. Additionally, it can integrate with continuous integration tools like Jenkins, making it easy to automate the build process. Yarn, on the other hand, is designed to work seamlessly with the npm package manager and build tools like webpack. It integrates well with modern front-end development workflows and can be easily integrated into the JavaScript build pipeline.

6. Community Adoption and Support: Maven has been widely adopted in the Java community and has a large user base. It has a rich documentation base, extensive online resources, and active community support. Many plugins and libraries are available for various development tasks. Yarn, being a relatively newer tool, has gained significant adoption in the JavaScript community, especially with the rise of Node.js. It has an active open-source community, and support is continuously improving as more developers adopt it.

In summary, Apache Maven and Yarn serve different purposes in the development ecosystem. Maven focuses on centralized dependency management and is primarily used for Java projects, while Yarn excels in managing packages and is commonly used for JavaScript projects.