It means an amount of information transmitted by an internet connect per unit time. It is specified as bits per second. The requirement of bandwidth depends on the rate of internet consumption done by you. If you are an avid internet user, then you can spend as much as you want on bandwidth. But if you just want it for updating your social life on a number of sites on the internet, then don’t go for a costly investment. And there’s another thing you need to know about, if you try to download a high def video then it would be downloaded without any pause but if you start adding other files to it, then the speed reduces as it is divided among other files. Network availability depends on how much bandwidth you are left with.