Libraries are a way to structure a project based on modularity, which allows the developer to split the code over multiple files and to share some piece of code or module with other developers.
Many programming languages use libraries to provide this modularity to the developer, and Dart is no different. In Dart, these libraries also have another important role besides code structuring. That is, they determine what is visible or not to other libraries.
Before we get into the Dart package, we need to understand the smallest unit that the library consists of. First, let's explore how to use a library inside our package and, following this, learn how to define a library in Dart.
