Shared Hosting: This option will be suitable for personal websites and most small to medium size websites. If you have large databases or expect a large amount of traffic to the website then you will need to consider a Virtual or Dedicated server.
Virtual Hosting: This option is suitable for medium to large size websites that are reliant on dedicated RAM and storage. They are ideal if your website will have a high volume of visitors/users and are also a good option for file and document storage.
Dedicated Hosting: If your website is mission critical to your business, then dedicated hosting is an option you need to consider. The resources on each machine are totally dedicated for your needs and therefore your website will respond much faster for visitors to the site. You also receive 24/7 monitoring and support with this option.