So many of us go to various presentations and sit and really wander what the presenter is actually talking about. Maybe it's a term that they keep using or something that just doesn't seem to make sense to us the way they are explaining it.
In IT there are times when people use various acronyms and don't explain what they are referring to before they start using the acronym. It can be very confusing because an acronym can mean a few things or it can even be a new one that you haven't heard before so you send a lot of time trying to figure out what the person is talking about.
A good presenter shouldn't mind if you ask questions because if you don't understand something you probably aren't the only one. It is sometimes a topic that is very advanced and that is what the problem is or maybe the presenter has made some assumptions about their audience without really knowing the level of the audience.
At one presentation I kept having an issue with one concept so I decided that maybe it was just me that didn't understand it so I asked the presenter one on one. The presenter was great and actually explained it to me and then I got it but during the explanation he realized that it was something that was missing in the presentation. Yes, it was an assumption that was being made about the audience. What was really nice was the presenter asked if I was going to his next talk and I was. During his next presentation on the topic, that I had been confused in, he made a point of making sure that the point was explained so that everyone understand eliminating the assumption. Since me asking my questions, I have seen that presentations relating to this process have more clearly explained the total process and didn't make assumptions.
It is important to realize that when you ask your questions you aren't trying to embarrass the presenter but get an understanding. There are some questions that are good to ask publicly but there are some questions that if possible are best asked privately or in a smaller group.
Asking a question is normally good because you gain the knowledge and understanding that is needed. Just remember that presenters are human and may not have all the answers quickly available during a presentation. If you don't get an answer but they have given a contact, reach out and maybe then you will get the answer you are looking for.