In the first clip below, I used a “simple” keyframe to move the text. The movement is linear.
In the second clip, I used the “advanced” keyframes feature, setting the keyframe type to “Smooth”.
The difference is subtle, but nevertheless the smooth option is better.
Cheers!
LINEAR:
SMOOTH:
Well, I wouldn’t say Smooth is necessarily better. It just depends on the purpose. For example, Smooth can give sometimes a jiggly effect that you might not want for a specific context and that’s where Linear would be perfect.
In any case, thanks for putting up those demo vids. 
Jon,
You totally ignored discreet key frames.
Discrete can be used to make hyper effects.
Interesting that for me with Chrome/Windows @jonray’s streamable embeds do not play inline whereas @sauron’s do.
Ditto. Although sauron’s post is one of the few times a streamable embedded video has played for whatever reason.
I use a variety of browsers in Windows, including Firefox, Chrome and Edge (eww… only when I’m at work), and experience the same thing, with no rhyme or reason, in any thread where streamable embeds exist.
Hi Sauron… I did! Actually I’m not totally sure what they do yet or how they work. Your video is great - have you any more examples?
It seems the discrete key frames let you create a jump effect. This is an another example of discrete key frames to create a rocking effect.
Very nice effect. Don’t suppose you have the mlt file of that handy to share?? 
Yup, seems that weird stuff is still going on with posting Streamable clips on this forum.
For me, Sauron’s first post wouldn’t play inline, but his second video did:
First post:
2nd post:
I started a thread on this a few months ago:
https://forum.shotcut.org/t/problems-viewing-demo-videos-from-streamable-com-on-this-forum/5720
I’m assuming the text links below the viewer work for everyone?
This one was fairly simple. Used the rotate and scale filter with discrete key frames.
Set the zoom to 200 at the start of the clip to keep the clip in frame. Set the rotation to 360 then timed the key frames to the drum beats alternating between 340 and 20 degree rotation.
Discrete.mlt (6.9 KB)
Discrete is also needed for some parameters where interpolation is not possible (e.g. strings) or does not work good (e.g. the color values in the Color Grading filter). Yes, the color values can be interpolated linearly or smoothly today, but the results are like not what you want/expect. In the case of strings, imagine if the Text filter let you change the text itself over time. That is theoretically possible but not yet available.
Thanks for the file, sauron! Will investigate when time allows…
Thank you Dan. Yet more stuff I’m learning about from this great forum 
Um…the vids aren’t loading.
People should not use the free streamable service for something like this, a tutorial resource. But I guess that service is not totally obvious that it is an ephemeral video service when you use its free account: