Want to know different between Sub and Function

Hi, I just start learning VB, and one thing confuse me is the Sub and Function, what is different between them, when should I use Sub and when should I use Function or which one is better, are they both the same ?
Thank You

in its simplest form:
A sub is used when you want a procedure that doesn't return any value.

A function returns a value after it has performed it's task.

Put a textbox nd a button on a form and type this:

VB Code:

Private Sub Command1_Click()
    Dim strRetVal As String
 
    'call sub
    Call MySub(Text1.Text)
 
    'call function
    strRetVal = MyFunction(Text1.Text)
    MsgBox strRetVal
 
End Sub
 
Public Sub MySub(strSubInput As String)
    Dim strTask As String
 
    strTask = "MySub " & strSubInput
    MsgBox strTask   'Show result
End Sub
 
Public Function MyFunction(StrFunctionInput As String) As String
    Dim strTask2 As String
    
    strTask2 = "MyFunction " & StrFunctionInput
    
    MyFunction = strTask2   'Return result to the calling procedure
End Function