Is Bitcoin the only cryptocurrency?

No. Bitcoin is not the only cryptocurrency. Stellar,, Ethereum,, Lightcoin are available in many cryptocurrency markets. Bitcoin is the most popular cryptocurrency.

Like bitcoin, ethereum also most popular and it is also can be withdrawn through ethereum to paypal

Crypto-The effort stake in currency has been going on for a long time. Researchers have learned that a currency that) can (be discovered from cryptography was found in the 80s., But they failed to solve some problems. In2008, an unknown researcher simply sent a research paper to the Internet forum smugly solving the problems. Surprisingly, his solution is useful. His solution is called "Block-Chain" The first crypto-Currency' was invented based on the block- the chain, called Bitcoin., Because of its high, prices, and the growth of the snout,, it is considered as wealth by most people, not a currency.

Then there are many other crypto-currencies,, such as Ripple,, Light Coin, etc. But Bitcoin is the first crypto, and many researchers, are ahead of others in being able to attract investors' attention. But another crypto-currency that could suddenly move forward and bankrupt Bitcoin, a major risk to investment. No one can say which one will go ahead.