I bought an iPhone 5s from a friend and used it as is. I'm now trying to sell the iPhone and I need to delete the content on the phone because I previously used it for work purposes and have private and confidential passwords etc on it. I have already deleted the files, but want the content completely deleted and unrecoverable. On a side note, I have recently been introduced to the functions of iCloud and was worried that these files may have been saved to the previous owners iCloud account. However, when I went to setting>iCloud, I was asked to sign in and there seemed to be no existing signed in account.
My questions are:
1. Is an Apple ID the same as iCloud accounts?
2. If there was no existing iCloud account signed into the iPhone for the duration of the time that I owned it, does this mean that the content is not floating around somewhere in the previous owners iCloud account?
3. Will restoring the iPhone to factory settings ensure that the content in unretrievable? Presuming that the content is not on an iCloud account.
4. If I restore the iPhone to factory settings while there's no existing iCloud signed in, does this mean I won't need to provide usernames and passwords to the iCloud account while setting up the iPhone? I'm not actually sure if the previous owner had an iCloud account or not, however it is not signed in to one.
5. How do I restore an iPhone to factory settings? I don't have an iTunes account, however I do have a macbook