CALL

CALL procname ([arglist])

Transfers control to a subroutine or function.

procname	The name of the procedure.
arglist	(Optional) The comma delimited list of variables to pass to the procedure.

REMARKS

* Using the Call keyword is considered redundant now, which is a shame. because it does make your code more readable.
* This syntax actually comes from the days of BASIC when every line had to start with a keyword.
* When you transfer control without using "Call" you do not have to include parentheses around your arguments.
* This can be used to call functions as well as subroutines.
* When you call a function the returned value is discarded.
* For the Microsoft documentation refer to learn.microsoft.com

procname arg1, arg2 
Call procname(arg1, arg2) 

Sub Testing() 
    MySubroutine1 
    Call MySubroutine1 

    MySubroutine2 20 
    Call MySubroutine2(20) 

   'ignores return value
    MyFunction1 
    Call MyFunction1   

    'ignores return value
    MyFunction2 "text" 
    Call MyFunction2("text") 
End Sub 

Sub MySubroutine1() 
    'nothing
End Sub 

Sub MySubroutine2(ByVal number As Double) 
    'nothing
End Sub 

Function MyFunction1() As String 
    MyFunction1 = "text" 
End Function 

Function MyFunction2(ByVal str As String) As String 
    MyFunction2 = "text" 
End Function