Microsoft office

HKChoo wrote:

Is this provided free of charge to iPad user?

No.

This is a Microsoft product not an Apple product.

Apple has its own office apps it supplies to iOS devices at no extra charge.

They are Pages, Numbers and Keynote.

You can get a free versions of MS Office applications that will enable you to open and view files. To have the full editing and creating functionality you need to buy an Office 365 subscription.