By registering using email, you can access your account from any browser on any device, simply by specifying this email as a login and specifying your password.
In the case of registration using Seed, private key, or Keystore File, registration occurs only for this device and only for this browser. As a result, you will be forced to create a password and import your account every time you clear your cache or use a new device or browser. We do not recommend using this method, as every time you provide your seed, private key, or Keystore File, they can be intercepted.