The main difference among wallets is the way they manage the private key of their users. Some wallets retain control of the private keys (custodians), while others leave the full control of the private keys to their users.
Custodians: there are many platforms that allow you to manage your funds, performing the same function of a bank where users can deposit funds. Users are provided with an interface to manage their funds but their private keys are stored in the servers of the wallet providers, representing a possible vector of attack
Among these types we count:
-Online wallets, that can take both the form of softwares or websites
Users have control over their private keys: this type of solution provides a higher degree of security, since they do not store the private key of their users on their servers. Therefore, the user has full control over the security of their funds.
Among these types we count:
-Mobile wallets: downloadable software for laptops or other devices.
-Hardware wallets: unlike software wallets, these wallets are small devices, similar to a normal usb key. The private keys are stored inside the device, guaranteeing an ever higher degree of security. Accessing the keys require physical possession of the device, making an attack even more difficult and complex.
