Online storage is a device that is connected to the internet at all times and it is used to store crypto and private keys of crypto accounts. Devices for online storage are practical and accessible. However, hackers can easily access them, which gives them the opportunity to steal sensitive and important data.
Because of this, even though online storage is very practical, it is unquestionably less secure than offline (or cold) storage. With offline storage, information is kept on hardware wallets and other internet-unconnected devices that cannot be remotely hacked.