One's website is placed on the same server as many other sites, ranging from a few sites to hundreds of websites. Typically, all domains may share a common pool of server resources, such as RAM and the CPU. The features available with this type of service can be quite basic and not flexible in terms of software and updates. Resellers often sell shared web hosting and web companies often have reseller accounts to provide hosting for clients.
Also, if your site uses more bandwidth than you’ve subscribed for, they’ll charge you for overuse. But so do most other providers. Therefore, it’s always good to keep accurate estimates of the traffic on your site. Bandwidth is not directly correlated to traffic, it depends on the simplicity and usage of your site. A simple website with 2-3 pages and with approximately 1000 visitors/mo would need around 1GB of bandwidth.