Searching for each cell in column A over another column in B

Hello everyone,
I have 2 columns in Excel which i want to check each row in column A for his identity in column B

For example:
Column A
204345
435643
232435
113435
689842
578324

Column B
5367885
578324
5972589
1234844
204345
478771

You can see that the value "204345" and "578324" in Column A have his identity in column B
if its true, i want to make the font bold in column A. if not, dont make it bold.

Can you help with that?
Thanks!

Maybe:

Sub moshiko17()
Dim i As Long
Dim y As Range
    For i = 2 To Range("A" & Rows.Count).End(3).Row
        Set y = Columns(2).Find(Cells(i, "A").Value, LookIn:=xlValues, lookat:=xlWhole)
            If Not y Is Nothing Then
                Cells(i, "A").Font.Bold = True
            End If
        Set y = Nothing
    Next i
        
End Sub

Alternative solution:
Apply this to the relevant worksheet's code

Sub Identify_yourself()

Dim row_number_1 As String
Dim row_number_2 As String
row_number_1 = Cells(1, 1).End(xlDown).Row
row_number_2 = Cells(1, 2).End(xlDown).Row
For i = 1 To row_number_1
For j = 1 To row_number_2
If Cells(i, 1).Value = Cells(j, 2).Value Then
Cells(i, 1).Font.Bold = True
End If
Next j
Next i

End Sub

WOW guys you are incredible awesome !!
thank you very much for your help.. !!!