Almost all applications, after development, need to go through a step called "build" before they are deployed. In some languages, it involves compiling the code. Some environments need to establish library dependencies or binary optimizations. In any case, there is often this step to take your code, process it and get the final distributable ready for deployment.
Depending on the application, the build process might vary in complexity from a single command to complex logic and scripting. Thankfully, there are tools to streamline, automate and optimize this step. Here you'll find courses to help you learn about such tools.