Component definition in Computer Security terms:

Acronym(s): None

Definition(s): An element of a large system, such as an identity card, issuer, card reader, or identity verification support, within the PIV system.
Source(s): FIPS 201-2

Any hardware, software, and/or firmware required to construct a CKMS.
Source(s): NIST SP 800-152

A software object, meant to interact with other components, encapsulating certain functionality or a set of functionalities. A component has a clearly defined interface and conforms to a prescribed behavior common to all components within an architecture.
Source(s): NIST SP 800-95 (Web Services Glossary – W3C Working Group Note 11 February 2004)

An element such as a fingerprint capture station or card reader used by an issuer, for which FIPS 201-2 has defined specific requirements.
Source(s): NIST SP 800-79-2

Synonym(s): Information System Component
A discrete, identifiable information technology asset (e.g., hardware, software, firmware) that represents a building block of an information system. Information system components include commercial information technology products.
Source(s): CNSSI 4009-2015 NIST SP 800-171 NIST SP 800-53 Rev. 4 A discrete identifiable IT asset that represents a building block of an information system.
Source(s): NIST SP 800-128


reference: CSRC Glossary