Are (computer science) workshops less prestigious than conferences in general? I am a PhD student in computer science and I have noticed that my advisor tries to avoid having me submit to workshops in my field when I bring workshops to his attention that we could submit to. He, instead, prefers to publish in a conference, journal, or IEEE/ACM magazine instead. I almost feel like he treats workshops as not prestigious enough.

The workshops I bring to his attention are all good workshops in my opinion. These workshops are IEEE and ACM workshops demanding original research papers that are about 6 pages long (conference papers in my field are usually 8 to 10 pages long). The program committees for these workshop are known people in my field and previous year's workshop papers have a 5 or 6 citations (for example), so they do get attention (but I don't know how this compares to the attention that this same paper could have gotten if it was published at a conference).

My questions are: are workshops viewed as less prestigious in general than conferences? Is there an unspoken understanding that only new, inexperienced students present their papers at workshops? Would having workshop papers in my resume somehow lower the credibility of my work?

(Apologies if the questions sound naive. I have always been unable to understand the 'prestige' of a 'co-located' workshop when juxtaposed against the conference.)
Workshops are usually for new topics, and I do rank them lower than conferences. Moreover, workshops usually publish/accept papers rejected from their co-located main conference; often than not, they are used to prop up the number of registrations or to cover the cost of the main conference.  Also, because they are new, it is usually very easy to get a paper accepted as the standard is not there yet.  However, if the topics of interest grow and attract experienced researchers, then a workshop can be quite hard to get into, and hence, its prestige grows.