I want to know whether there is any way I can use Emacs as Terminal in Ubuntu. Means, I want to do the basic works with Emacs that I usually do with Terminal in Ubuntu, like 'sudo apt-get update'. I'll write this command and it'll update my Ubuntu system. Is that possible?
You have a couple options, the perform the same basic function but there are some subtle differences. First you have M-term. This is a full fledged shell inside of an Emacs frame and responds the same as a terminal window and runs in it's own buffer. The issues I have with this is that you cannot switch buffers while the terminal is active, you must
exit before changing buffers or performing any other common emacs tasks.
Your other option is M-eshell. This is a seemingly mor lightweight option that runs on top of your current buffer and allows you to switch buffers and execute Emacs commands from the mini-buffer while using eshell.
You might want to read over this emacswiki page, has lots of good info on the topic.
I did it. I used 'M-x Shell' in Emacs. That's it.