Considering dedicated versus shared services? What's the difference really? Shared service like a big city with lots of unrelated people sharing resources. Things are usually peaceful in the city, but sometimes the people get in each other's way, cause traffic jams, disturb the peace or worse. With a dedicated server, you have an island fortress, a space and resources reserved just for you.
A dedicated server provides increased security and privacy through a physical separation from unrelated customers. You are much less at risk if another customer is attacked or hacked. Increased reliability because you do not have to share memory, CPU, network disc space and other resources with other customers and a possibly better reputation as your server's address is not also doing things for others.
Additionally, unlimited service tiers are exclusively available on dedicated servers. The only limit is the power of the server you choose to purchase. Dedicated is best for accounts that need hundreds or thousands of users or gigabytes of storage, secure web hosting, security or compliance and maximum reliability.