The Camera Snapshot Button is located at the leftmost on the 3D area, as shown in image bellow
Snapshot: This button allows you to capture formal camera snapshot quickly. A snapshot is generally the capture of an object's state at a specific moment in time.
Don't be confused between Snapshot button and Capture Image button. Snapshot is about preserving informative scene state to be used later, whereas Capture Image is about generating an image from the viewer as it is in the 3D-Area or a rendered image if rendering process is turned on.
To delete a snapshot or a collection of taken snapshots, go to the Scene State Library which you can find under the Scene State tab on the Scene Building ribbon after switching to the Scene Building workbench.