upgrade Ubuntu 16.04 without losing data [duplicate]

I am using Ubuntu 14.04 LTS. I want to upgarde to Ubuntu 16.04 via the software updater application. I have lots of data in my laptop. Also I am having useful softwares related with my work. Now I wish to upgrade my system without losing any data and software. Ca n I do it?. or else what is the procedure to upgrade Ubuntu without losing old data.

As @Mark Kirby says, this is a probable duplicate of "Can I smoothly upgrade from one LTS to next LTS release?". The basic answer, is yes you can upgrade smoothly from one LTS (long term service) release (say 14.04 LTS) to another (say 16.04) without installing intermediates.

You can do this for Desktop LTS releases with the commands:

sudo do-release-upgrade

or

sudo update-manager -d

... and for the Server LTS releases with the commands:

sudo apt-get install update-manager-core
sudo do-release-upgrade

HOWEVER, I would say that I've watched plenty of "tested" software that's relatively widely used break, malfunction, or otherwise work improperly, so I would suggest a basic backup of your home directory to an appropriate form of external storage, i.e.

mkdir /mnt/<external storage>/May_30_2016_Backup_Ubuntu_16_04_Upgrade
cp -rf ${HOME}/* May_30_2016*/ &

This is generally a good practice, as even if everything works perfectly, maybe your hard drive dies tomorrow (also has happened to me). Now you'll be thankful you have that backup, even if you didn't seemingly need it.