In dedicated server you buy full room (server) on rent, This is optimal for people that have high traffics per month. Dedicated hosting is much costly than VPS shared hosting. Many websites have not too many visitors per month, so they can choose VPS shared hosting. If your visitors limit less than 100k per month, then you have to choose Shared web hosting. Shared web hosting is suitable for beginners and those users that have less traffic on the website. I hope you understand about web hosting.