What do 'wide shot' and 'long shot' mean in photography and video?

[I need to come back to this with more time tomorrow & bring my almost famous bear & bookcase]

Long & wide are not polar opposites.

Either can be based on lens focal length and/or distance from the subject.

A wide shot is one that encompasses more than just the subject. It could be the whole room, an entire street, or a city-scape taken from a helicopter.
In video, this would be called an establishing shot, before closing in on the action of the next scene. Stills photography doesn't really have an equivalent, as usually each picture is meant to stand alone.

Let's take just 'a room' as a simple example.
One person standing in a room. You want to show a lot of 'context' i.e. the room, with a small subject.
In a large room, you can achieve a wide shot by simply moving the camera away. Done.
In a small room, where you don't have the space to create that distance, instead you would use a wide lens - one with a focal length under 24mm or so.

The opposite of 'wide' is, in fact 'tight'.
In our room example, just a shot of the subject's upper body, or even ECU [extreme close up] just the head, or eyes.

A 'long shot' can be simply one taken from a large distance.
In itself, it doesn't describe how long the lens is - so a long shot can also be a wide shot.
It could also be a tight shot taken with a long lens.