What is the difference between device updates "on" and "direct messages" on twitter?

[Kelccccie]

[brayden]

Direct messages are private tweets that you send to someone/someone sends to you. Each user on twitter has a direct message inbox. If someone sends you a DM then you, and only you, can read it. Anyone who is looking you up and checking out your tweets, can not see any of your DMs.

You can send DMs or even public tweets directly from the twitter box when you log in, from a device such as a mobile phone, or from a 3d party software.

You can go into settings on your account and select it where your device (mobile phone) receives your direct messages. And if you do, it means only your direct messages will go to your device.