Remember slide film? Carousels and projectors and hauling out the big screen to see those vacation photos? Are you old enough to remember high school and/or college lectures on slides? The shop techs remember.
Nowadays everyone’s much more likely to use Slides than slides, of course. More portable, for the most part. Easier to edit, up until the last moment. Overall, a lot of advantages. But the old-school ones were pretty cool, too.
One can only hope that back in the days of the Audio-Visual Aids Department (we’re assuming they’ve been subsumed into L&IT, but not ruling out the possibility of a now-defunct academic department), they wheeled these – and film projectors, and VCRs, and hopefully LaserDiscs, too – into your classroom space on the classic steel cart. Embedded YouTube clips just aren’t the same.