I think it can mean different things in different cases. Swanson brought up the example of concepts. Of course they exist, but do they exist in the same way as a table, a chair, or a tree? They don’t exist materially do they? Could you rearrange the molecular structure of a concept? I don’t think so.
I think the best way to approach the question: “What does it mean to exist?” is to not assume that it has only one meaning. One should examine a particular case and then ask: “In what sense does it exist?”