Hemicordulia australiae (Australian Emerald)IUCN Status: Least Concern.
There are 324
species of dragonflies and damsel flies in Australia. That's a pretty big number. Yet most people are completely unaware that such diversity exists. Some people I've been showing photos to had even though that all the dragonflies were the same. I've had the same thing happen with frogs.
Once you start looking though, there very distinct differences between some dragonfly species, from their colouration, to the way they hold their wings when perched, and your brain starts to spot these differences easily.
However, for some the differences are very, very subtle. For example, with this spieces, the identifying feature is how close the yellow pattern on abdomen segments 6 and 7 comes together at the front top. For damselflies, the differences can be even slighter, and the specimens are smaller.