How to implement ethereum address for exchange?

[wsxdrfv]

so I installed geth console and run as testnet.

So next step is generate account.

So here ethereum is different with Bitcoin. Bitcoin just spit out address. But ethereum is like,

(at geth console)

> personal.newAccount("testuser1")
"0x13019fghjklejg12438091hjflkdsj"

So ethereum's all address require account? (string value)

Ethereum address also has private key? Where is it?

How apply to exchange?