Molly E. Reynolds and Margaret Taylor offer a useful description of What’s in the House Resolution on Impeachment?:
First, the resolution directs all six committees instructed by Speaker of the House Nancy Pelosi to participate in the inquiry—Intelligence, Financial Services, Foreign Affairs, Judiciary, Oversight and Reform, and Ways and Means—to “continue their ongoing investigations as part of the existing House of Representatives inquiry.” This posture—directing a continuation of work rather than authorizing the inquiry—reflects House Democrats’ long-standing assertion that the impeachment inquiry need not be specifically authorized by the full House to be valid. In addition, it would seem the scope of the inquiry, at least for now, is not strictly limited to issues related to President Trump’s conduct with respect to Ukraine. It is hard to say whether issues being investigated in other committees will eventually find their way into articles of impeachment, but this resolution certainly leaves that possibility open.
(Reynolds and Taylor continue with a thorough description.)
Embedded below, the resolution and a fact sheet from the House Committee on Rules: