These beautiful shrubs or small trees are both members of the Rhododendron family, which confuses me even more.
Flower specialists say that there are many differences between the two species; I remember three of them, that are easy to observe:
1. Rhododendron flowers have 10 or more stamens, while Azaleas just five.
Than this pink-lavender flower in the picture is a Rhododendron.
2. Also Azaleas usually have just one flower per stem while rhododendrons have their flowers in clusters.
This white-pink beauty must be an Azalea.
In the next picture, these are the flowers of a white rhododendron tree.
3. Another difference between Azaleas and Rhododendrons can be observed on their leaves.
Rhododendrons have glossy, leathery leaves while some Azalea leaves are thinner, hairy and more pointed.
These two beautiful shrubs have different light requirements as well: Azaleas love full sun unlike rhododendrons which prefer full shade.