Here's what I have and what i have defined. Everything that I have as #not sure about this is what I don't understand. I want to learn the SolidWorks API code and I don't know what certain definitions and tasks are doing in this macro. The yellow highlighted part is the code. Thanks again for any help.

Option Explicit   #Not sure yet

Dim swApp As SldWorks.SldWorks                            #This defines the application as Solidworks

Dim swModel As SldWorks.ModelDoc2                  #This defines swModel as the Solidworks model document

Dim swSketchMgr As SldWorks.SketchManager                                 #This defines swSketchMgr as the sketch manager for creating sketches in SolidWorks

Dim swExcel As Excel.Application                               #This defines swExcel as the Microsoft Excel application

Dim exSheet As Excel.Worksheet #This defines the excel spreadsheet as the document to use in the macro for exporting numbers for Solidworks to use

Dim i As Integer                                #This defines i as an integer to use for various tasks

Dim xpt As Double                           #Not sure about this part yet

Dim ypt As Double                           #Not sure about this part yet

Dim zpt As Double #Not sure about this part yet

Dim xpt1 As Double #Not sure about this part yet

Dim ypt1 As Double                        #Not sure about this part yet

Dim zpt1 As Double                        #Not sure about this part yet

Sub main() #sets apart the definitions from the actual applications procedures or commands

    Set swApp = Application.SldWorks                        #Sets up the application

    Set swModel = swApp.ActiveDoc                          #Prepares to use the active document for the entity to which the properties will act in

    If swModel Is Nothing Then                     #Is a double check procedure to make sure an active document is open for editing

        MsgBox "Please activate a part document before using this macro."                                                 #is a warning from the macro application to the user on why it will not function

        Exit Sub                        #Exits the current set of commands in the macro and returns to an offline state until the user changes the error so the next run will execute the macro properly

    End If                                 #Ends the if command loop

    If swModel.GetType <> 1 Then                             #Not sure

        MsgBox "Please activate a part document before using this macro."

        Exit Sub                        #Exits the current set of commands in the macro and returns to an offline state until the user changes the error so the next run will execute the macro properly

    End If                 #Ends the If command loop

     If Not swModel.GetActiveSketch2 Is Nothing Then                                    #Not sure yet

        MsgBox "Please exit the sketch before running this macro."                               #is a warning from the macro application to the user on why it will not function

        Exit Sub                        #Exits the current set of commands in the macro and returns to an offline state until the user changes the error so the next run will execute the macro properly

    End If                 #Ends the If command loop

                                #Code has passed the initial tests. Will start the next commands for the macro

    Set swExcel = GetObject(, "Excel.Application")                              #Will open up the excel application for the macro

    Set exSheet = swExcel.ActiveSheet                                     #Takes the activesheet for importing data

    Set swSketchMgr = swModel.SketchManager                                #Sets the sketch manager open in Solidworks

    swModel.ClearSelection2 True                                              #Clears any selection the mouse is clicked on

    swModel.SketchManager.Insert3DSketch True             #Is activating the 3D sketch for Solidworks

    swModel.SetAddToDB True                                                    #Not sure yet

i = 1                                                                                                        #Defines the integer i as 1

      Do While exSheet.Cells(i, 1).Value <> ""                          #Not sure yet

        xpt = exSheet.Cells(i, 1).Value / 1000                              #Takes the excel spreadsheet i-A and divides its value by 1000 for the x1-point

        ypt = exSheet.Cells(i, 2).Value / 1000                              #Takes the excel spreadsheet i-B and divides its value by 1000 for the y1-point

        zpt = exSheet.Cells(i, 3).Value / 1000                              #Takes the excel spreadsheet i-C and divides its value by 1000 for the z1-point

        xpt1 = exSheet.Cells(i, 4).Value / 1000                           #Takes the excel spreadsheet i-D and divides its value by 1000 for the x2-point

        ypt1 = exSheet.Cells(i, 5).Value / 1000                           #Takes the excel spreadsheet i-E and divides its value by 1000 for the y2-point

        zpt1 = exSheet.Cells(i, 6).Value / 1000                            #Takes the excel spreadsheet i-F and divides its value by 1000 for the z2-point

        swModel.SketchManager.CreateLine xpt, ypt, zpt, xpt1, ypt1, zpt1                                 #Creates a line based on the values from the above commands

i = i + 1                                  #defines the next i value as i+1 so the next column will be selected as 2-A 2-B ect

Loop                                      #defines the loop so the command starts again at i=current value at end of the loop when 1 is added from the previous step

    swModel.ViewZoomtofit2                       #Zooms the Solidwork application to fit the view of all the line segments drawn

    swModel.SetAddToDB False                  #Not sure yet

    swModel.ClearSelection                           #Clears the selection manager from the current operation

    swModel.SketchManager.Insert3DSketch True                             #Not quite sure yet

    swModel.ClearSelection2 True                              #Clears the selection manager

End Sub                                #Ends the macro