Differentiating between graphical and connection lag

When submitting lag reports, please describe clearly the type of lag you're experiencing!
Here's a quick guide to differentiating between the both:

Graphical Lag
* Jerky animation
* Screen freezes or hangs for a moment, especially during spell-casting or with heavy animation involved

Connection Lag
* Significantly delayed response between clicks when talking to NPCs
* Monsters do not die or receive damage
* Monsters and party members float across the map, or "teleport" around at random intervals