On its most basic level, Padlet is a collection of virtual sticky notes where many users can collaborate on the same bulletin board. In this example, the teacher has provided a word of the day, and the students have all posted their own example of using the word in a sentence. All the students need is a weblink to your Padlet, and they can immediately post their thinking on it.
The canvas itself is completely customizable, so students can notate on top of any image you would like. You can even make your own interactive maps.
Padlet is a great tool for brainstorming, collaboration, and project organization.
It can also used as a presentation tool to show student learning. Here is an example where a student has made a timeline with embedded images and videos.
Here is a video tutorial for Padlet as well as some ideas of how to use it in the classroom.
Here is a Pinterest collection of Padlet ideas.