A Level Computer Science WJEC

Hardware and Communication

Hardware

• Processors: Central Processing Units (CPUs) are essential for executing program instructions. They perform arithmetic, logical, control and input/output operations within a computer system.
• Main Memory: RAM (Random Access Memory) is vital for temporarily holding data and program instructions that the CPU uses frequently. ROM (Read Only Memory) is the non-volatile part of the main memory which retains data when power is switched off.
• Secondary Memory: This includes hard disks, optical disks and solid state drives. They provide long-term storage of files and programs.
• Input/Output Devices: These peripherals (e.g. keyboards, mice, monitors, printers) send and receive data to and from the computer system.
• Buses: Connect all components in a computer system allowing data to be transmitted.
• Understand the Von Neumann architecture. It's a computer design model where the storage and the processor share the same memory space.
• Also comprehend the Fetch-Decode-Execute cycle that underpins how any computer works.

Communication

• Understand network topologies like Star, Bus, Ring and Mesh. They're important for knowing how devices are connected in a network.
• Know the different types of networks: Local Area Network (LAN), Wide Area Network (WAN), Metropolitan Area Network (MAN), and Personal Area Network (PAN).
• Learn about network protocols (e.g. HTTP, FTP, TCP/IP, SMTP, POP3, IMAP). They govern how data is transferred across a network.
• Identify the difference between routable and non-routable protocols.
• Be familiar with the Client-Server model where servers provide resources and services to clients.
• Get to know about Peer-to-Peer networking which allows resources sharing among network devices without the need of a central server.
• Understand the concept of Virtual Networks and their benefits: e.g. VPNs that provide privacy and greater security online.
• Grasp how cloud computing provides on-demand network access to shared computing resources.
• Have a clear concept of hardware and software firewalls, which are instrumental for network security.