Difference between pagecontrol and pageviewcontroller ios ?

What is the difference between UIpageControl and UIpageViewController? What are their use case where these control should used ?

I have created a uipageviewcontroller demo in which i created a pageviewcontroller and for its content i have taken a content view where i am using a image view to change the image on each left or right gesture by user (But haven't used the gesture function for them). When i try to left/right scroll them image just load and disappear and the view which is root view appear.

How can i remove this bug?