USD still popular over high popular is compare bitcoin
you wrong is compare, maybe compare dollar paypal , dollar perfectmoney dollar okpay is right placed compare
is comare USD not equal, USD real curency in the world , bitcoin digital curency
I have no idea what you are trying to say but for me I think USD is still better currency in compare to bitcoin as it can be used anywhere to buy anything.
it is not a better currency at all, bitcoins are the best because they are not controled by any banks or other financial institutions
But Bitcoin is essentially controlled by major mining pools now. They seem not to exercise their power (at least, openly), but apart from that, they are just like any other financial institution which has control over money (the US dollar or whatever)...
So what's the difference really?
The difference is that USD is privately issued. Therefore USD issuers can issue any amount at any time, at no cost to the issuer, and we the people have no way to know or verify that it happened.
BTC is publicly issued - any new coins are announced publicly and verifiably to all participants. Such coinbase events are limited in amount and frequency, and only appear when proof of costly work has been presented.