Typically a regular paper presentation would be 15-30 minutes in length, accompanied by a visual presentation (such as PowerPoint). Short papers tend to have shorter presentation slots (10-15 minutes usually).
Poster presentations require a printed poster, usually size A0 and the presenter is responsible for preparing and printing of the material. The organizer usually provides poster holders and adhesives, unless specified otherwise.
The timing of the slots is determined by the program chairs and all presenters will be informed about the length of presentations and any technical details.