Well a straight answer to this question is “GNU/Emacs is a text editor” which can be easily extended and customized. But I would say its an Operating system in which one can do anything from managing other processes, files, folders, check mails, browse web and even listen to music apart from just editing text and writing codes. For developers and coders it acts as an full fledged IDE.
Git is a version control software used to manage documents and source-code of a software program over time and between people. As we know that the software changes with time with many updates and BUG fixes. Sometimes it happens such that the latest changes implemented in a source-code makes it completely unusable, and if the copy of the previous working code is not kept safely, all the work is in vain.
Newbies often get confused with the concept of GNU and Linux. Most people end up saying GNU/Linux as ‘Linux’. The important thing here to understand is most people don’t directly use Linux. This may sound contradict but Linux is just a core part of an operating system. It’s task is to handle underlying hardware.
Users work on application, and applications can’t talk directly to hardware, they take help of Linux-kernel. Major Free and Open source applications(Libre Office, VLC media player etc.) are licensed under GNU License. In fact the basic core-utils packages used in Linux like copy, move etc. are GNU applications.
Ubuntu is a free and opensource operating system based on GNU/Linux philosophy. It is first appeared in 20th October 2004. It is a fork of Debian Linux distribution. The present version of Ubuntu supports variety of devices such as tablets, netbooks etc. It can even be installed as an app inside Android mobile operating system.
A free and open source operating system. The main component of Linux is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds.
Today Linux runs supercomputers, cellphones, laptops, tablets, webcams, music systems, gaming consoles, GPS, automations, robotics, space shuttles and almost any thing which has
a processor 200 MHz or above.