Online wallet: advantages and disadvantages
The advantages include:
Speed and intuitiveness of working with the service;
Accessibility from anywhere in the world where there is Internet;
Cross-platform: access from any device that has Internet access via a browser;
Convenience when traveling and shopping online;
The best option for beginners and for operations with small amounts of BTC.
The disadvantages include:
Wallet security depends on a third-party resource;
Wallets are loaded from a remote server;
Many online wallets can fully control your bitcoins, as the keys are stored on the service's servers.