A steel beam carries loads across an opening or distance towards supports. Its section belongs to a designed structural arrangement, including connections and the components that receive the transferred forces. The visible beam is only part of that system.
How this term relates to your project
In a wall opening, bearings, supporting construction and connections must suit the proposal. Ask how the beam position affects ceiling height, finishes and new frames. A slim detail in a reference image may not be appropriate for your house. Do not substitute a readily available section without having the change assessed.
Discuss how the component reaches its position and how temporary support is arranged. These questions belong with the structural designer and contractor, rather than a generic online sizing table. Record the selected arrangement with the associated drawings so the eventual finish does not obscure the information needed for future alterations.