Odd 'Where' statements

I'm familiar with SQL syntax but have not used SQL Server before. I am using 2008 Enterprise.

I used Filter in the Designer Editor. In my text field I put the string Abel. I ran the query and it found the record but Im baffled with the synbatx generated:

WHERE (LastName = N'Abel')

Where's the N come from?

Thanks

N just means it is unicode strings.