Your business may be an online one. Otherwise, you may have a traditional brick and mortar business but you want to take advantage of the internetcraze by having your own website for your business.
In order to have a webpage for your business, you will need to use web hosting with either dedicated servers or shared servers. Most smaller businesses can deal with shared servers because they don't need much bandwidth, space and attention.
More complex online businesses, however, may require a dedicated server particularly if they are receiving plenty of online visitors per day. Online businesses which have websites that contain plenty of pages and information will need dedicated servers that can handle that amount of online data storage.