Comparing data- simple???

Hello,

there is probably a very simple answer to this but i can not work it out! i have self taught myself excel and struggling with the below and would really apprechiate some advice!

I have tried Vlookup but seem to just get a value error??

I have 2 sheets where I need to compare 2 separate pieces of data

column A- employee (mix of letters and numbers)
column B- departments

1) I need to be able to see if any employees have been added or removed from the new spreadsheet
2) I need to see if any of the employees have moved departments but still live

Thank you