Difference between Stored procedure and User Functions

Fundamental difference between Stored procedure vs User Functions:

• Procedure may return none or more values.Function must always return one value either a scalar value or a table.
  
• Procedure have input,output parameters.Functions have only input parameters.
  
• Stored procedures are called independently by EXEC command whereas Functions are called from within SQL statement.
  
• Functions can be called from procedure.Procedures cannot be called from function.
  
• Exception can be handled in Procedure by try-catch block but try-catch block cannot be used in a function.(error-handling)
  
• Transaction management possible in procedure but not in function.