Present Continuous and Present Simple 1

Compare:
Present Continuous (I am doing)

we use the the continuous for things happening at or around the time of speaking; the action is not complete.


 Present Simple (I do)

we use the present simple for things in general or things that happen repeatedly

compare:
- The water is boiling. / - The water boils at 100 degrees Celsius.
- Let's go out, it isn't raining now. / - It doesn't rain very much in this region.

- I'm getting hungry.  / - I always get hungry in the evening

We use the continuous for temporary situations:
- I am living with my parents until i find a place of my own. /
- My parents live in Madrid; they have lived there all their lives.

Also:
- I always do (something) = I do it every time : 
I always go to University by car

- "I am always doing something" has a different meaning.
I' ve lost my keys again! I'm always losing things!