[nekopa]

This really depends on the presentation. Of course, you should be in control of the presentation, and let your audience know wether or not they can ask questions at any time, or at the end, or, if you've designed a well structured presentation, take questions at the end of each 'part' of your presentation.

The reason why it depends is if you're presenting something complex, say A and B and C, and if understanding B requires understanding A, and understanding C requires understanding A and B there is nothing worse than reaching the end of the presentation and the first question is 'What exactly did you mean by A?' and a lot of nodding heads. That means no one got two thirds of your presentation.

I've been teaching presentation skills for about a decade, and I've seen the above scenario plenty of times, mainly in legal presentations, but also in tech and sales presentations.