Is your specimen a Damselfly (Zygoptera) or Dragonfly (Anisoptera)?
The technical difference is actually wing shape – fore-wing shape compared to hind-wing shape. If you can see it, are they similar or dissimilar?
Damselfly: both wings similarly shaped.
Dragonfly: hind-wing broader than fore-wing
Sometimes a more visually obvious distinction from some angles, though, may be the head shape.
Which head shape does your specimen have?
Damselfly: dumbbell shaped head
Dragonfly: spherical head