How to securely erase an iPhone 5
I bought an iPhone 6S fro yesterday. Besides it, i also owned an iPhone 5 for 2 years. There is no need to keep two iPhones at once, so i will sell the old one to someone. However, before selling i want make sure everything being wiped on that phone. How can I erase my iPhone 5 securely that the buyer can't get any information from the phone.