There are several different types of Bitcoin wallets, but the most important distinction is in relation to who is in control of the private keys required to spend the bitcoins. Some Bitcoin “wallets” actually act more like banks because they are holding the user’s private keys on behalf. If you choose to use one of these services, be aware that you are completely at their mercy regarding the security of your bitcoins. Most wallets, however, allow the user to be in charge of their own private keys. This means that no one in the entire world can access your account without your permission. It also means that no one can help you if you forget your password or otherwise lose access to your private keys. If you decide you want to own a lot of Bitcoin it would be a good idea to divide them among several different wallets. As they saying goes, don’t put all your eggs in one basket.