The private account setting is your account and only you can take actions with this.
This is the most secure setting, but since it’s private, you can’t use it to display syncs or Salesforce info in the doc.
Shared account setting
A shared account is required to display Salesforce data in a doc.
Setting this to “Take actions and view data” will mean that anyone who has edit access to the doc will be able to act as you when taking actions from Coda to Salesforce.
Disconnect a shared account
You can easily disconnect a shared account if you change your mind and would like to remove your credentials.