to talk about a subject with someone and tell each other your ideas or opinions

The police want to discuss these recent racist attacks with local people. 警方希望与当地人讨论近期发生的种族主义袭击事件。

to talk or write about a subject in detail, especially considering different ideas and opinions related to it

The later chapters discuss the effects on the environment. 后面的几章阐述了对环境产生的影响。