Can anyone please explain to me exactly what Anxiety is?

[RasAlGhoul]

I mean i know i have Anxiety but im not sure what it is truly, what i know that it is an intense stress for a long period of time that triggers many stress response and very often due to external objects in the real life such as a voice, sound, sight a taste of anything that triggers a bad memory and the worry about it.

Is there anything i am missing?