Hi again!
Another question, I hope I'm not being too annoying with these!
I'm having a bit of trouble distinguishing between a few types of markings on sheet music. Specifically:

As I understand it, the "slur" above means that the pitches should be played continously and without any "pauses" between them.

In the image above, as I understand it the dots above the notes mean that the pitches should be played with a very short "pause" between them, so you play the first two notes, then lift your fingers for a micro second and play the other two pitches.
Now, if I got the two above correctly...

Then what does a typical notation like this refer to? How should it be played?