Why is wget much faster than downloading via Chrome?

I tried to download a gigabyted file where I got 200~300 kb/s in my browser but the same link worked in wget over 6MB/s...Is there some magic behind the command?

wget normally works a little bit faster than Chrome because it's a terminal program so there is less resource usage overhead, but that would not explain such a large difference in download speeds between wget and Chrome. You probably have an issue with downloading that large file in Chrome. wget is a better tool than Chrome for downloading large files, if you don't have to solve a captcha in order to download the file.

The discrepancies in speed that you are seeing can easily be explained by variable server load. Although I have seen high rates of throughput with wget, I've also seen relatively low rates. However, I've never seen a discrepancy in speed of the magnitude you mention, so I'm certain there is another variable that you are not considering. My experience tells me that the load on the server or network segment(s) you were using was higher when you got the lower rates and lower when you got the higher ones. This assumes that the tests were done on the same hardware using the same network interface. Different hardware can provide huge discrepancies in results. For example, you'll never get anywhere near the throughput on a netbook with a 100Mbps interface (or WiFi) that you'll get from a well built desktop with a Gigabit interface. Real world tests prove that properly designed and built hardware can provide throughput 30 times or more throughput off the same server on the same network segment. There are more variables involved than one might think. The speed of the storage media, the network interface, the bus(FSB) and even the RAM speed can have an impact on throughput. As others have mentioned the software itself CAN impact the speed of transmission, but the difference is usually minimal in my experience.