There are many types of wallets that people use for Bitcoin. People manage their Bitcoin addresses with wallets on their PC, through a website, smartphone applications, specific hardware, or even by keeping things written down on paper. An eWallet allows for simple account creation which can be accessed from a computer. Since the level of security is determined by the operator of the website be sure to use one that is trustworthy.
Third party websites can be targets of hacking so it is not recommended to use them for managing particularly large amounts of Bitcoin.