Scientific conferences can be one of the means to disseminate new knowledge, advances of projects and lines of research already informed previously.
The drawback of this method of disseminating information and knowledge is that it can not be deepened or extended in argumentation or support of the evidence, for which the ideal complement is a scientific publication in form.
Formal scientific publication, either as an essay, a theoretical proposal or results of a research guided by hypothesis testing.
Of course, the way in which the conference is held and presented, reveals the level of preparation and professional competence of an academic, teacher or researcher in its area of competence: scientific, technical and innovative.
In the yester years these scientific conferences are quite useful for personal enrichment and development. But today such time of atmosphere is really missing
The actual objective of a scientific conference is to bring together several experts of a subject field at one place for showcasing new research, laying the foundation for potential collaborations, getting new ideas and understanding the latest developments in a discipline. I personally feel that the present-day conferences are more limited to pure get-together, sometimes even resembling a picnic.
Conferences are a forum to discuss, exchange and build a view on the concerned subject. But it is very sad to say that conferences are now a days meant for getting together, sightseeing etc.
I assume that a "department" belongs to an institute or company that consists of a whole number of departments. In this respect, a departmental conference is not a special event that attracts many participants with expectations, but a working meeting as it is held at least once a week in every institute - or in every department.
There are conferences very helpful, valuable, causing real effect on your research ourcomes in the future.
There are "networking" conference (mainly big congresses) where you have to be since your participation serves as some simbolic belonging to a certain group of scientists.
There are conferences that are pure waste of time.
A lot depends on you: you have to be able to choose conferences that will serve your development. But even from boring and inconsequential conferences, you can get something out if you listen carefully.