If you are using android for a long time and now you are going to buy iPhone. So be careful before buying, get to know the following things which may affect your user experience.
On android phone, you have much freedom. But on iPhone there are many restrictions.
These are the things you can not do in your iPhone:
You can not download songs from any website to your gallery
If you get any incoming call, it will not be minimized even if you do not want to attend that call and you are working on some important work on mobile.
You can not expand memory by adding external memory card
You can not change iPhone UI or can not customize UI in iPhone
You can not charge iphone with any other charger. You need only iphone charges
You are can free to download apps from anywhere. You can download and install apps only from app store.