The Intent class had 6 constructors
Intent()
Create an empty intent.
Inten
Activity inherits context. Thus, if you are in an activity, you only need to pass itself to use the context. It also contains a pointer to getBaseContext(). You might occasionally need to reference that, if you need the entire application context, but most likely you won't for a while.
You can find more details about the Activity class here.
This question about the intent constructor parameters is similar to yours and has a really good answer. I think you'd like to check it out.
Hope it helps.