What is the difference between Logical connection and User connections?
I looked into the Books Online Doc, it says


  Number of logical connections to the system.
  
  The main purpose of logical connections is to service multiple active
  result sets (MARS) requests. For MARS requests, every time that an
  application makes a connection to SQL Server, there may be more than
  one logical connection that corresponds to a physical connection.
  
  When MARS is not used, the ratio between physical and logical
  connections is 1:1. Therefore, every time that an application makes a
  connection to SQL Server, logical connections will increase by 1.