Difference between XP office andMS office

Hello Friends,
I am a Windows administrator. I work on Windows Server as well as editing all the documents required for the project. My client asked me to upgrade from XP office to MS office. I Googled for the difference between the boat but couldn’t get a clear idea.
I want you to help me and make me know the difference between the both applications so that I can use all the advanced features in MS office and also explain my client, if I am asked.
Thanks for the ideas.
