In very simple words remote desktop is a sharing between one computer to other computer in the via internet.
you can access the another computer remotely (sharing access without infront of your computer )
There are so many remote desktops are there but in my experience i would like to suggest these below two remote desktops is very easy and fast also free
Access all your computers and servers remotely around the clock. Need access to your computers on the road? Need access to your customer’s unattended servers? No problem – with TeamViewer all host installations are free.
Access and back up your home or work computer from anywhere with an Internet connection. Even access your desktop from your iPhone or other computer. It's fast, easy and secure.
