Build tools are essential applications in software development that automate the process of compiling source code, managing dependencies, and preparing software for deployment. They streamline various tasks, such as compiling code, running tests, and packaging applications, which enhances efficiency and reduces manual errors. By automating these repetitive processes, build tools allow developers to focus more on writing code rather than managing the build lifecycle. Popular build tools, such as Maven and Gradle, are widely used in different programming environments, particularly in Java development, to facilitate continuous integration and improve overall productivity in software projects.