A Hot Wallet in digital currency refers to any kind of online storage wallet.
Hot storage wallets can be accessible from anywhere from a web portal. These kind of wallet are usually not recommended because the wallet is stored online, which makes it susceptible to hacking.
However, any type of wallet which is stored offline is termed as Cold Storage Wallet. These kind of wallets are more secure, as they are stored physically and hackers do not have any access to them.