In Computer Science, does a presentation of findings at a conference constitute a "publication"?
There are two types of publications in Computer Science:


Publications in peer-reviewed conferences with published proceedings
Publications in journals


If you present your results at a conference or workshop but don't publish them in the conference proceedings — it's not a publication.

In general, publications in top tier conferences are much more important than journal publications for computer science researchers. Usually you can first publish your paper in conference proceedings and then submit it to a journal but not the other way around (though, of course, that depends on conference and journal policies).