What does those numbers located at both ends of an airport runway mean?

Question

Recently, I went to Sandakan. Our aeroplane flew past Kota Kinabalu International Airport (BKI). I noticed that on the airport runway, there was a number 20. In Google Earth, I also noticed the same number 20. But now both sides of the runway has a number. 20 on one side and 02 on the other side. I also checked Sandakan Airport on Google Earth and its runway also had two numbers. 08 and 26. What is the use of painting those numbers on the runway? And why for each airport the numbers differs?

Answer 1

they all called runway numbers.  google it, or visit the Wiki site that I have provided below for detailed information on how and why they are numbered.

http://en.wikipedia.org/wiki/Runway

Answer 2

It's the runway number. When a plane requests clearance to takeoff or land, they're given a specific runway to do it on.