Learned that EC2 service for AWS is the backbone of almost everything. From my understanding, almost all services will be linked to it in some way shape or form.

What is an EC2?

From my knowledge, it is a virtual machine created through AWS. That is HIGHLY customizable. Things such as the amount of memory, networking, or whether it'll be a dedicated host or instance and so much more. You can create one easily with just a few clicks, or use cloud formation and create several that way.

Dedicated host vs instance?

I believe if your using a Dedicated host, you can have an entire rack of servers for yourself while instance is just a single one for yourself.