It's a free app that will be preinstalled with Windows 10, and you don't need an Office 365 subscription to use it. You can download the new Office app from the Microsoft Store, and it's rolling out to existing Windows 10 users over the coming weeks.
Do all laptops come with Microsoft Office installed? Not all laptops come with installed Office programs. You might be able to install Office alternatives such as Open Office on them or simply purchase a subscription on Microsoft's website.