CCEA A-Level Digital Technology A2 1 Information Systems: a complete overview of networks, databases, AI, cloud and the law

What this unit demands

A2 1 Information Systems is the largest content unit of CCEA A-Level Digital Technology. It extends the AS fundamentals into networked, multi-user systems and their consequences: how computers connect and communicate, how data is structured and queried in relational databases, the emerging technologies of AI, cloud and big data, and the law and ethics that govern them. The examiners test precise theory (especially databases) and balanced discussion (especially the emerging-technology and legal topics).

This guide ties the unit's dot points together. Each topic has its own page with worked questions; this overview shows how they connect.

Networks, protocols and transmission

Networks are classed by scale (LAN, WAN, PAN) and arranged in topologies (bus, star, ring, mesh), built from switches, routers and network cards. Protocols such as TCP/IP are agreed rules that let different devices communicate, data travels over wired or wireless media, and error detection (parity, checksums, check digits) keeps it intact, usually triggering re-transmission on a fault.

Databases

Relational databases store data in linked tables with primary and foreign keys. ER modelling captures entities and relationships, and normalisation to third normal form removes redundancy and anomalies. Databases are queried with SQL (SELECT, INSERT, UPDATE, DELETE, with filters, sorts and joins) or visually with query by example, optimised with indexing, kept correct with integrity rules, and secured with access rights, encryption and backup, with concurrency control for many users.

Emerging technologies

Artificial intelligence powers expert systems (knowledge base, inference engine, user interface), natural language and voice recognition, and robotics. Cloud computing delivers software, platforms and infrastructure as a service, and mobile technologies give constant connectivity and location-based services. Data mining finds patterns in big data (volume, velocity, variety). Each has clear benefits and equally clear limitations.

Law and ethics

Data protection, computer misuse and copyright legislation govern how data and software are used, and digital technology raises wider moral, ethical and social issues, privacy, surveillance, the digital divide and automation, that the law does not fully settle.

How this unit is examined

A typical CCEA profile for A2 1:

• Database theory and practice. Keys, normalisation to 3NF, and writing SQL queries.
• Description. Network topologies, expert-system components, cloud service models.
• Discussion. Balanced benefits and drawbacks of AI, cloud, mobile and data mining.
• Application of law. Identifying which legislation applies and the duties it imposes.

Check your knowledge

A mix of theory, query and discussion questions covering the unit. Attempt them under timed conditions, then check against the solutions.

1. Distinguish between a LAN and a WAN. (2 marks)
2. State one advantage and one disadvantage of a star topology. (2 marks)
3. Explain the difference between a primary key and a foreign key. (2 marks)
4. State the condition for a table to be in third normal form. (1 mark)
5. Write an SQL query to list the name and town of customers in 'Belfast'. (3 marks)
6. Name the three components of an expert system. (3 marks)
7. Give one benefit and one risk of cloud computing. (2 marks)
8. Name the legislation that makes hacking an offence. (1 mark)