Sansom IT define your IT infrastructure as the background hardware and software that deliver your applications and data to your computers/ desktops. Your IT infrastructure is made up of Server, Storage and Network components, both hardware and software. There are functions that secure and support these components such as Backup and Restore, VPN connectivity, Antivirus and Disaster Recovery to name a few.
When the industry refers to Infrastructure Services they refer to the elements above, grouped and shaped into specific services. For instance, Infrastructure as a Service (IaaS) generally refers to server and storage services delivered out of a vendors data centre facility. You will see other functions as a service such as Back-up (BaaS) and Disaster Recovery (DRaaS). Vendors usually group Messaging, Collaboration, and Desktop offerings under infrastructure services as well.
Having an IT infrastructure environment that is aligned to your business needs is important for controling costs, securing company IP and delivering technolgy where and when it is needed.
Click here to view the Information Technology Infrastructure Library (ITIL) v3 definition