Speedtest - check the speed of your internet
Internet speedtest tests ping (latency), download speed and upload speed of your internet connection. There are several factors that can affect your internet connection speed at any given time, other than what type of connection you have, such as cable or DSL. If several people in one house are online at the same time, playing games and streaming music or videos, the internet speed will be slower than usually is. Also, the age of your computer or modem could be a factor, because the technology is constantly improving.
Download speed result is how efficiently music, photos and videos, or information goes from a website or other sources on the internet to your computer.
Upload speed result is the opposite of download. This tells you how efficiently pictures or files transfer from your computer to another site, such as uploading a video to a social network.
Even more information about internet speed you can find in this article from Wikipedia.