Derech Eretz has a handful of meanings.
The most common in everyday speech is behaving respectfully. Of course we are supposed to treat everyone with respect, but the term is most often used when teaching children to have Derech Eretz for parents and any rebbe or menahel or rosh yeshiva in school, as well as adults. Kids are taught to “have derech eretz” for a rebbe when enters a class room. It can be seen as the opposite of chutzpah.
The second most common spin on derech eretz, i believe, is as a synonym for mensch.
Third most popular meaning of Derech Eretz afaik refers to earning a living (parnassa).
This is not an exhaustive list.