Connection to a wireless network allows you to perform simple things like checking your email, browsing the net, conferencing, and other basic stuff. On the other hand it is not advisable to use wireless networks to stream audios or videos, download anything that is large or open web sites that have powerful graphics.
Although wireless networks are good enough you will still get the better performance and higher speeds from wired networks. In general wireless connection works similarly as Ethernet connection, with a speed of approximately 11 megabits per second. The only setback in wireless connection is that you have to share the bandwidth with other users and that slows down the network. Furthermore, it makes intensive operations harder to execute. Now that is the reason why wireless networks will never be same as the wired Ethernet network when it comes to speed.