$ cat /etc/passwd | grep username
The root account is the administrative account on Linux; this account has control over everything in the system.
root
Linux is an operating system for the computer. You can purchase computers that already have Linux pre-installed on the computer. Select Dell computers come equipped with Linux.
Yes Ubuntu-linux offers the "install along side windows" option.
Android is a Linux based operating system means you are already running Linux over your smart device ! And you can switch Android with some other Linux version !
Yes. Linux can either replace the existing system or be installed alongside it in what is called "dual-booting."
Linux is a stable operating system for using free office software such as LibreOffice. Many varieties of Linux already have LibreOffice installed by default.
GCC is already for the most part preinstalled in many, if not all, GNU/Linux distributions.
By default,there is only one account, root. However, most Linux distribution will either allow or make you set up a second administrative user account.
It is difficult to measure, but most experts agree that Linux is quickly expanding on the desktop market. On other markets Linux has already had a pretty strong presence, in many it already is the dominant operating system (Servers, Cluster/Farm Computing, Supercomputers.).
This is generally not necessary. Unlike in Windows, most Linux systems have all the drivers they need already present. This means if your card is not supported out of the box, there is either no driver for it at all, or it is in development and would probably not work correctly anyway. In short: you don't.
For the most part, every Unix-based and Unix-like (and by extension, Linux) distribution will have a root account (equivalent to a system administrator account in Windows). The remaining accounts will be allocated for the users and for certain applications.