SD card question

[Guest mumug]

I have I9100 & I9103 and inserted 8GB SD card in both phones. But I notice that the phones built-in memory already called itself SD card. The SD card I inserted called external_sd.

So the programs installed and copied to SD card were only copied to phone memory. Titanium backup was also backup to phone memory.

I don't understand how to use the real SD card "external_sd". Any advise please.