For those not in the know, let us first discuss what Linux is. It is not an application program; it is an operating system, in the same class as Windows or Apple’s Mac OS. An operating system is the piece of software that makes it possible to run any other application or user software on a computer. The operating system manages and provides the ability for programs to access the computer’s hardware, and it provides security mechanisms such as password-protected accounts that control user access. Operating systems have evolved into highly complex, multi-layered conglomerations that are essential to the operation of a computer.
Now then, your question essentially is whether Linux is a viable replacement for Windows. As usual, the answer is “that depends”. Specifically, it depends on what you want to do with the machine, and how much time you’re willing to put into learning about Linux. Where Windows is a vendor-built and supported operating system, Linux is open-source. That means the code base is public, and not supported by a company. Instead, it is supported by the community of users who contribute to its development. Since nobody “owns” Linux the way Microsoft owns Windows, it also means that multiple “flavors” of it exist – at least six or seven depending on how you count them.