Identify if string exists, copy entire row.

this updates sheet2 from sheet1 and if it not in sheet1 and no sheet 2 it adds it to sheet2 for

Option Explicit
Sub ptest()
    Dim ws1 As Worksheet, ws2 As Worksheet
    Dim lastRow As Long, i As Long, found As Range
    Application.ScreenUpdating = False
    With ThisWorkbook
        Set ws1 = .Sheets("Sheet1")
        Set ws2 = .Sheets("Sheet2")
    End With
    lastRow = ws1.Cells(Rows.Count, "a").End(xlUp).Row
    For i = 1 To ws1.Cells(Rows.Count, "a").End(xlUp).Row
        Set found = ws2.Range("a:a").Find(ws1.Cells(i, "a"), LookIn:=xlValues, LookAt:=xlWhole)
        If Not found Is Nothing Then
            ws1.Cells(i, "A").Resize(, 9).Copy Destination:=ws2.Cells(found.Row, "a")
        Else
            ws1.Cells(i, "A").Resize(, 9).Copy Destination:=ws2.Cells(ws2.Rows.Count, "a").End(xlUp).Offset(1, 0)
        End If
    Next i
    Set ws2 = Nothing: Set ws1 = Nothing
    Set found = Nothing
    Application.ScreenUpdating = True
End Sub