how to install , Remove , Update , Upgrade packages or software on Linux/Ubuntu

Thats too simple , Lets see how

• Install a Package: Installation of packages using the apt-get tool is quite simple. For example, to install the network scanner nmap, type the following:
  

  sudo apt-get install nmap
  

• Remove a Package: Removal of a package or packages is also a straightforward and simple process. To remove the nmap package installed in the previous example, type the following:
  

  sudo apt-get remove nmap
  

  
  

  	Multiple Packages: You may specify multiple packages to be installed or removed, separated by spaces.

  Also, adding the --purge options to apt-get remove will remove the package configuration files as well. This may or may not be the desired effect so use with caution.
• Update the Package Index: The APT package index is essentially a database of available packages from the repositories defined in the /etc/apt/sources.list file. To update the local package index with the latest changes made in repositories, type the following:
  

  sudo apt-get update
  

• Upgrade Packages: Over time, updated versions of packages currently installed on your computer may become available from the package repositories (for example security updates). To upgrade your system, first update your package index as outlined above, and then type:
  

  sudo apt-get upgrade