Accounts

Hello, how do brokers manage your accounts. Lets say you open an account, does this mean there is a REAL account. Meaning, an account on my name at a bank. Or is my account just a thing in their administration.

I am asking this because at Forex.com my accountnumber is not a number but a code in fact it's my username to log in into the trading platform. So I w

'Or is my account just a thing in their administration.' <--- that's it!

So what are my rights then when I want my money and they zipped my account which is not more then an internal registration. How do I proove I have money with them, obviously I can download all kinds of reports from my platform like Transaction Loggings etcetera. But how strong are these reports.