Application rationalization is the process of identifying which business applications should be kept, replaced, retired or consolidated across an organization to improve business operations.
Hosted services are outsourced information technology (IT) systems and functions. A hosted service provider owns and oversees infrastructure, software and administrative tasks and makes the system available to clients, usually over the Internet.
An ISV (independent software vendor) makes and sells software products that run on a physical hardware device, on a virtual machine or in the cloud.
Managed hosting is an IT operations model in which a service provider leases dedicated servers and associated hardware to a single client. The equipment is at the hosting provider's facility and managed there.