Developers do not often pay attention to licenses when using various open-source projects. We can often use projects/part of a project or functions for our applications and programs without thinking about how it might affect the future. Do you need to keep the copyright? What are the requirements and obligations of different licenses? In this article, I want to highlight the issue of choosing licenses for the project and the specifics of using projects with different types of licenses. 

Here and below, the project refers to an open-source project or repository.