What type of services are NOT directly used by the business but are required by the service provider to deliver customer facing services?

Business services are IT services that directly support business processes and are visible and consumed by the business units.

Component services is not the standard ITIL term for this category; supporting services is the correct terminology used in the ITIL service catalog context.

Supporting services are internal services that the service provider relies on to deliver external, customer-facing services - for example, a shared infrastructure service used to run a customer application. The business never interacts with them directly, but without them the customer-facing service cannot function. This is a key distinction in ITIL service portfolio and service catalog design.

Customer services are those directly delivered to and consumed by external customers, which is the opposite of the hidden, infrastructure-level services described in the question.