title: What is the difference between SYSTEM_USER and USER in SQL server?
body: <p>I am very new to databases and confused between the keywords <a href="http://technet.microsoft.com/en-us/library/ms179930.aspx" rel="nofollow">SYSTEM_USER</a> and <a href="http://technet.microsoft.com/en-us/library/ms186738.aspx" rel="nofollow">USER</a> in MSSQL. The definitions say that they return the username in the current context. but the instance I have running returns 'dbo' for USER and 'sa' for system user.</p>
  
  <p>Can somebody highlight the exact difference between the two?</p>