Below is an A - Z guide of commonly used terms
when discussing biometrics:

Attempt
The submission of a biometric sample to a biometric system for identification or verification. A biometric system may allow more than one attempt to identify or verify.

BEM
Biometric Evaluation Methodology

BioAPI
Biometrics Application Programming Interface standard.

Biometric
A measurable physical characteristic or personal behavioral trait used to recognize the identity of an enrollee or verify a claimed identity.

Biometric application
The use to which a biometric system is put.

Biometric data
Extracted information taken from a biometric sample and used either to build a reference template on enrolment, or to compare against a previously created reference template.

Biometric feature
A representation from a biometric sample extracted by the extraction system.

Biometric sample
A biometric measure presented by the user and captured by the data collection system.

Biometric system
An automated system capable of capturing a biometric sample from an end user, extracting biometric data from the sample, comparing the data with one or more reference templates, deciding on how well they match, and indicating whether or not an identification or verification of identity has been achieved.
Note that in CC evaluation terms, a biometric system may be a product or may be (part of) a system for evaluation.

Biometric template
See template.

Capture
The process of taking a biometric sample via a sensor from a user.

CBEFF
Common Biometric Exchange File Format standard

CCEM
Common Criteria Evaluation Methodology [CEM]

Common Criteria
An international scheme for the security evaluation and certification of IT systems.

Comparison
The process of comparing biometric data with a previously stored reference template (or templates).

EAL
Evaluation Assurance Level

Enrollee
A user with a stored biometric reference template on file.

Enrolment
The process of collecting biometric sample(s) from a person, and the subsequent preparation and storage of reference template(s) and associated data representing that person's identity.

Failure to acquire rate (FTA)
The failure to acquire rate is the proportion of attempts for which a biometric system is unable to capture an image of sufficient quality. When a biometric system allows multiple attempts, FTA measures failure to capture over these multiple attempts.

Failure to enroll rate (FTE)
The failure to enroll rate is the proportion of the user population for whom the biometric system is unable to generate reference templates of sufficient quality. It is the equivalent of FTA for the enrolment process, and depends on the procedures used in enrolment (which may differ from the procedures for later identification). It includes those who, for physical or behavioral reasons, are unable to present the required biometric feature.

False Acceptance
An incorrect identification of an individual, or an incorrect verification of an impostor.

False Accept Rate (FAR)
The probability that a biometric system will incorrectly identify an individual, or will fail to reject an impostor. For a positive (verification) system, it can be estimated from: (the number of false acceptances) ÷ (the number of impostor verification attempts).

False Match Rate (FMR)
The rate for incorrect positive matches by the matching algorithm for single template comparison attempts. For a biometric system that uses just one attempt to decide acceptance, FMR is the same as FAR. When multiple attempts are combined in some manner to decide acceptance, FAR is more meaningful at the system level than FMR.

False Non-Match Rate (FNMR)
The rate for incorrect negative matches by the matching algorithm for single template comparison attempts. For a biometric system that uses just one attempt to decide acceptance, FNMR is the same as FRR. When multiple attempts are combined in some manner to decide acceptance, FRR is more meaningful at the system level than FNMR.

False Rejection
A failure to identify or verify a genuine enrollee.

False Reject Rate (FRR)
The probability that a biometric system will fail to identify a genuine enrollee. For a positive (verification) system, it can be estimated from: (the number of false rejects) ÷ (the number of enrollee verification attempts).

Identification
The process of using a submitted biometric sample for comparison against the set of enrolled templates to match a user to an enrollee. (Normally used only in one-to-many systems)

Identification system
Identification systems, where the user makes no explicit claim to identity, may be compared to verification systems. Without a claimed identity, the biometric system does a one-to-many process of comparison against all enrollees in its database.

Impostor
A person making a false claim about identity to the biometric system.

Live processing
Direct enrolment/ identification of potential users via the normal biometric capture process. Compare off-line processing.

Matching score
A measure of similarity or dissimilarity between the biometric data and a stored template, used in the comparison process.

Multimodal biometric
A biometric device which uses information from different biometrics - e.g. fingerprint and hand shape; or fingerprints from two separate fingers. All statistical analysis of multimodal systems should consider how the modes are combined in the comparison process.

NIST
National Institute of Standards and Technology

One-to-many matching
See identification system.

One-to-one matching
See verification system.

On-line processing
See live processing.

Operational testing
Testing a biometric system to measure its statistical properties (e.g. FAR and FRR) in a specified operational environment, with a specific target population.

Physical/ Physiological biometric
A biometric which is characterized by a physical characteristic.

Positive claim
A claim by a user to be enrolled in the biometric system. An explicit claim is often accompanied by a user identification, and may also be associated with a password or PIN.

PP
Protection Profile. A form of generic Security Target defined in the Common Criteria.

Receiver Operating Characteristics (ROC)
A method of showing the performance of the biometric system over a range of decision criteria - usually shown as a graph that relates FAR to FRR as the decision threshold varies.

ROC
Receiver Operating Characteristics

Scenario testing
Testing a biometric system to measure its statistical properties (e.g. FAR and FRR) in an environment modelled to simulate a particular application.

Security Target
A set of security requirements and specifications to be used as the basis for the evaluation of a TOE.

Sensor
The physical hardware device used for biometric capture

Sensor ageing
The gradual degradation in performance of a sensor over time.

Technology testing
Testing one or more biometric systems to measure statistical properties (e.g. FAR and FRR) to compare various algorithms and technologies - usually achieved by off-line processing.

Template
A user's stored reference measure based on biometric feature(s) extracted from biometric sample(s).

Template ageing
The gradual change of a user's biometric feature(s) which requires periodic updating of the user's reference template.

Threat
An intentional or unintentional potential event that could compromise the security integrity of the system.

Threshold
A parametric value used to convert a matching score to a decision. A threshold change will usually change both FAR and FRR - as FAR decreases, FRR increases.

User
A person who requires access to the portal which is protected by a biometric system.

Verification
The process of using a submitted biometric sample for comparison against a template to match a user to a known enrolee. (Normally used only in one-to-one systems, where the user may also have to specify a user name and/or password or PIN)

Verification system
Verification systems, where the user explicitly claims an identity, may be compared to identification systems.

Vulnerability
The potential for the function of a biometric system to be compromised by e.g. intention (fraudulent activity); design flaw (including usage error); accident; hardware failure; or external environmental condition.

Weak Template
A template created from a noisy, poor quality, highly varying or null image, which typically has a higher FAR than other templates.