Data engineering is nominally more pipeline oriented and less concerned with the governance & people side of things, but good data engineering people end up driving a lot of data management work because that's what makes the data engineering less painful (eliminate root cause of data errors and annoying data requests) and data overall more useful and valuable.

Data Management is an organization discipline -- it is about how the enterprise manages data as an asset and how data is embedded in the organization. This includes data governance issues like common data models, and a chain of command (which person/role is responsible for which piece of data), but also second-tier data processes such as quality control and data valuation.