Irish Leaving Certificate Glossary — Key Terms

Leaving Certificate: The state examination taken by students in Ireland at the end of secondary school, typically at age 17–18.

SEC (State Examinations Commission): The body responsible for setting, marking, and certifying the Leaving Certificate exams.

Ordinary Level (O-Level): The standard level of examination, suitable for most students.

Higher Level (H-Level): The more advanced level, required for competitive university courses.

LC (Leaving Certificate): The qualification itself, with grades ranging from H1/O1 to H8/O8.

Junior Certificate: The examination taken at the end of Junior Cycle (age approximately 15), a prerequisite for the Leaving Certificate.

Transition Year (TY): An optional year between Junior and Senior Cycle focused on personal development, work experience, and extracurricular activities.

Sixth Year: The final year of secondary school when the Leaving Certificate is taken.

Subjects: Students typically sit 6–7 subjects, with the best 6 counting for their CAO points score.

Foundation Level: The lowest level of examination in some subjects, available at Junior Certificate but not typically at Leaving Certificate.

Senior Cycle: The final two or three years of secondary school, including Transition Year, Fifth Year, and Sixth Year.

H1: 90–100%, 100 CAO points.

H2: 80–89%, 88 CAO points.

H3: 70–79%, 77 CAO points.

H4: 60–69%, 66 CAO points.

H5: 40–59%, 56 CAO points.

H6: 30–39%, 46 CAO points.

H7: 20–29%, 37 CAO points.

H8: Below 20%, 0 CAO points.

O1: 80–100%, 56 CAO points.

O2: 70–79%, 46 CAO points.

O3: 55–69%, 37 CAO points.

O4: 40–54%, 28 CAO points.

CAO Points Score: The total of the best 6 subject grades, used for university admissions.

Bonus Points for Higher Level Maths: An additional 25 points are awarded for achieving H6 or above in Higher Level Mathematics.

Paper 1: The first exam paper for a subject, typically covering specific topics.

Paper 2: The second exam paper, typically covering different topics.

Marking Scheme: The SEC’s official guide showing how marks are awarded for each question.

Coursework: Practical assessment components in subjects like Construction Studies, Engineering, and Home Economics.

Project: Extended practical work assessed as part of certain subjects.

Oral Examination: Spoken assessments in modern languages (French, German, Spanish, Irish).

Aural Examination: Listening comprehension tests in modern languages.

Practical Examination: Hands-on assessments in science, technology, and arts subjects.

Lab Work: Practical laboratory exercises assessed as part of science subjects.

Project Assessment: Extended research or practical projects assessed as part of certain subjects.

Cell Biology: The study of cell structure, organelles, and membrane transport.

Ecology: The study of ecosystems, energy flow, and nutrient cycling.

Genetics: The study of inheritance, DNA, and gene expression.

Plant Biology: Photosynthesis, transpiration, and plant responses to stimuli.

Human Body: Organ systems, homeostasis, and disease.

DNA (Deoxyribonucleic Acid): The molecule carrying genetic instructions.

Enzymes: Biological catalysts that speed up chemical reactions.

Homeostasis: Maintenance of a stable internal environment.

Photosynthesis: Conversion of light energy to chemical energy in plants.

Respiration: Release of energy from glucose in cells.

Immune System: The body’s defence against pathogens.

Atomic Structure: Electron configuration, periodic trends, and isotopes.

Bonding: Ionic, covalent, and metallic bonding.

Stoichiometry: Mole concept, balancing equations, and yield calculations.

Acids and Bases: pH, titrations, and neutralisation reactions.

Organic Chemistry: Hydrocarbons, functional groups, and reactions.

Mole Concept: The unit of amount of substance, 6.022 × 10²³ particles.

Enthalpy: Heat content of a chemical system at constant pressure.

Equilibrium: State where forward and reverse reaction rates are equal.

Electrochemistry: Galvanic cells, electrolysis, and the Nernst equation.

Functional Group: An atom or group of atoms defining the chemical properties of an organic compound.

Periodic Table: A tabular arrangement of chemical elements organised by atomic number, electron configuration, and recurring chemical properties.

Hardware: Physical components of a computer system.

Programming: Writing instructions for computers to execute.

Databases: Organised collections of structured data.

Networks: Connected computers sharing resources.

Algorithms: Step-by-step procedures for solving problems.

SQL (Structured Query Language): Language for managing relational databases.

Binary: The base-2 number system used by computers.

Boolean Logic: Logic using true/false values and operators AND, OR, NOT.

Pseudocode: Human-readable description of an algorithm.

Recursion: A function calling itself to solve smaller instances of a problem.

Abstraction: The process of removing physical details to focus on essential features.

Algebra: Manipulating symbols and expressions to solve equations.

Calculus: Study of rates of change (differentiation) and accumulation (integration).

Geometry: Properties of shapes, space, and spatial relationships.

Trigonometry: Relationships between angles and side ratios in triangles.

Probability: The likelihood of events occurring.

Statistics: Collection, analysis, and interpretation of data.

Sequences: Ordered lists of numbers following patterns (arithmetic, geometric).

Series: The sum of terms in a sequence.

Functions: Relations mapping inputs to outputs.

Limits: The value a function approaches as the input approaches a point.

Financial Mathematics: Interest rates, depreciation, annuities, and amortisation.

Mechanics: Motion, forces, and Newton’s laws.

Waves: Wave properties, sound, light, and diffraction.

Electricity: Circuits, voltage, current, resistance, and power.

Heat: Thermal energy, specific heat capacity, and specific latent heat.

Modern Physics: Radioactivity, nuclear reactions, and the photoelectric effect.

Energy: The capacity to do work, existing in various forms.

Momentum: Product of mass and velocity.

Electromagnetic Spectrum: Range of all electromagnetic radiation.

Nuclear Physics: Structure of the nucleus, radioactive decay, and nuclear reactions.

Quantum: Discrete packets of energy.

Optics: The behaviour and properties of light, including reflection, refraction, and lenses.

CAO (Central Applications Office): The organisation processing applications for Irish undergraduate courses.

CAO Points Score: Total of the best 6 subject grades, used for course allocation.

First Preference Points: The minimum CAO points for entry to a course’s first-choice applicants.

Offer Round: The scheduled dates when CAO offers are issued to applicants.

Round 1 (Round A): The first offer round, typically in August after results.

Round 2 (Round B): Subsequent rounds for remaining places and changes of mind.

Deferral: Postponing university entry for a year after receiving an offer.

Mature Applicant: Students applying to university based on work experience or mature years rather than Leaving Certificate results.

Non-CAO Application: Direct applications to some institutions such as private colleges and international universities.

Apprenticeship: A work-based training programme combining on-the-job training with classroom learning.

PLC (Post-Leaving Certificate): A further education course taken after the Leaving Certificate, often used as a pathway to higher education.

Available Points: The CAO points required for a specific course in a given year, published after each offer round.

• See GCSE Glossary for UK qualification comparison
• See A-Level Glossary for UK university entry
• See IB Glossary for international qualification
• See University Physics Glossary for deeper physics coverage
• See Mathematics Glossary for university-level mathematics