Windows XP Home

When I look in the security tabs under managing computer I see the following:
USER Catagory
Guest Logon/Logoff
System Account Logon
Anonymous Logon Logon/Logoff
Network service Policy Change
Local Service Logon/Logoff
This in addition to the regular user. Can anyone explain what is happening? Do I have a hacker hacking into my computer or is this regular XP’s doing?