If you have not contacted the network then you probably do not know the hosts file, even you do not know the file. Not to mention you'll know what it does, and this file is useless for most people because you don't have to change it. But sometimes it's very useful.
Hosts file windows/system32/drivers/etc/directory, used to control domain name access. If you add 127.0.0.1 www.baidu.com to the Hosts file, you can make your computer inaccessible and want to keep your computer from accessing any Web site. A lot of times you can use this to control the kids playing web games. This can be regarded as a hosts file magical.
The Hosts file can also speed up access to the Web, but the future you need to know the IP address of the site
Similarly, you play web games feel the computer is too card, you can use this method to do.
Hosts file is only used to control the domain name, that is, if you visit a website, this site in the Hosts file, then it will access the hosts file in the IP is not access to the network IP. Most of the time, especially the people who build stations are very useful.
The above is about the hosts file, the effect of the hosts file. Very useful also very practical, especially for some people, sometimes use it to make a prank is also good, such as the other people's computer Baidu to get a website.