Installing multiple packages at the same time

How do I install multiple packages?

For example, I want to install both package X and Package Y, I know that this is not possible by default but is there any alternate way of doing this or Can I atleast queue them for installation?

You can do this, why not!? You can run the following single command to install package-x and package-y:

sudo apt-get install package-x package-y

It has been mentioned that you can add the -y flag to apt-get to answer Yes to all the prompts. This usually only saves you from having to say Yes once, anyways. It's nice to know about the -y flag, but be careful, because it can also automatically remove things that you may not want removed. Typically, I omit the -y flag and manually review all Added or Removed packages to prevent myself from making mistakes that could have horrible affects on my computer. However, apt-get upgrade -y seems to be a good option and less volatile.

sudo apt-get upgrade package-x package-y -y

To install packages use:

sudo apt-get install package-name

To install multiple packages simply list one after the other:

sudo apt-get install package-name1 package-name2 package-name3

To force apt-get install to answer yes to any are you sure you want to install this package? questions which may arise add a -y to the end

sudo apt-get install package1 package2 package3 -y

I'm not sure about other users but I find it helpful to keep a file that has a list of all packages/programs that I commonly use so that in the event I need to reinstall I can simply copy and paste the command rather than having to spend the next few weeks figuring out what I have and haven't got.

As Angel identified below keeping a copy of dpkg --get-selections will allow you to keep handy all the packages you had in case of reinstall. You can also restore pkg metadata by using apt-mark showauto > auto.lst and apt-mark showmanual > manual.lst to get metadata and apt-mark auto < auto.lst and apt-mark manual.lst to restore it.

In Linux, apt-get/yum/etc can be compared to an "Installer" in windows. One installer can install only one software at a time. You can always install 2 or more software from source, binaries in parallel. Most Linux distributions have a common package manager, or "installer" for most software supported by that distribution. Unlike windows, in which each software comes with its own installer and hence they run in parallel.

In case you were seeking this