This tutorial introduces how to connect to the Raspberry Pi via VNC remote desktop. The prerequisite is that your Raspberry Pi needs to have the Jessie Pixel image installed, as the VNC server is pre-installed in the Jessie Pixel image. We only need to enable the VNC service in raspi-config. There is no need to install and configure additional software on the Raspberry Pi, and all that’s left is to install vncviewer on the controlling device.
Next is the specific operation process. First, let’s briefly introduce what VNC software is: 
Then, prepare to enable the VNC service on the Raspberry Pi. Here we need to use the Raspberry Pi configuration tool. Enter the following command in the terminal: sudo raspi-config to open the configuration interface, where you can configure some common and important functions of the Raspberry Pi.
I believe it is best to familiarize yourself with a new system when learning it. If you can accomplish tasks using the functions provided by the system itself, there’s no need for us to spend extra effort downloading, installing, and configuring other software. Utilizing the functions provided by the Raspberry Pi can save us a lot of effort. 
After successfully enabling the VNC service on the Raspberry Pi, a small VNC icon will appear in the upper right corner of the desktop. Once the service is successfully enabled, every time we reboot the Raspberry Pi after a power outage, the VNC service will start automatically without any additional configuration. 
Next, you need to install the vncviewer software on the Ubuntu system (the system that needs to connect to the Raspberry Pi remotely). The download link is: https://www.realvnc.com/download/viewer/linux/. Of course, you can also install the Windows client or Mac client according to your own system.
The downloaded gz installation package is about 2.4MB. After extracting, you need to add execution permissions.
Extract command: gunzip -c VNC-Viewer-6.0.1-Linux-x64.gz > vncViewer
Add execution permission: chmod +x vncViewer
Finally, enter the Raspberry Pi’s username and password to connect to the Raspberry Pi interface, and you can operate it just like on the Raspberry Pi’s touchscreen, although there may be occasional delays.
This concludes the tutorial. If you want to watch the complete demonstration video, you can search for “ROS Classroom” on Youku, and the specific video link is: http://v.youku.com/v_show/id_XMTkzODkwNTM1Mg==.html. Due to my limited ability, if there are any problems or errors in the tutorial, please leave a message, and I will discuss it with everyone and correct it in a timely manner.