Yes Impatiens are consider an annual flower. However if you live in hardiness zones 9-11, that will grow as a perennial.
The scientific or taxonomic name would be Impatiens wallerana.
When a flower is considered as an annual, it means that it will only grow 1 season. It germinates, grows , flowers and sets seed in one year.
psss.. it's a incomplete flower ! duhh
Azelea is a shrub so, by definition it would be perennial. An annual is a plant you sow and flowere and harvest in the same year