How does contact management work? I've got a Samsung Galaxy 3 with Android 4.1.2. I changed my SIM card today and was worried I might lose contact so I've backed them up. I've always found the contacts very confusing and obviously I messed up the restore process and I now have hundreds of duplicates, single contacts appearing up to 20 times. To be precise - they are not exactly 20x the same, but say for a person 4 times the phone number as separate contacts, 12 times for two different email addresses, 4 times for Skype etc ...

I've tried to push them all to Gmail and delete/edit them online and then reimport, but it seems that step missed quite a few contacts that have only phone numbers.

I also have to admit that I totally don't understand how all the contacts are separated internally (on SIM, on SD, Google, Samsung; import to/from/merge/push/blabla ... why can't there be a single list of contacts).

I know I am not able to clean the contacts up on the phone - there's simply too many.

So question: what would be the best way out of this chaos?

Thanks heaps

EDIT: ok, kind of did it. Superbackup app, uploaded to Gmail, imported, merged and de-duped by Google, exported tp vcf, deleted old vcf files on phone, figured out where Android wanted the new vcf, reimported ... and looks halfway sane. But there must be an easier way, right?
There is a single list of contacts. But smartphones allow many different contact providers (Google Contacts, Facebook, SIM card, internal phone contacts, Skype, ...). But they are all shown within the same app in a single list. A symbol tells you where the contact came from.

I recommend to use Google Contacts as main contacts provider. Don't save contacts on the SIM card and the internal phone memory. Google contacts are automatically synced with your phone and the cloud. You can comfortably edit the contacts @ google.com/contacts. Every edit is instantly propagated to your phone. And if you change your device you simply add your Google account and all your contacts will appear there, too. No more SIM card contact importing/exporting.

In order to solve the problem of duplicate contacts from different contact providers Android provides a 'join contacts' feature, which merges the information from different providers into one single contact.