What is a low-level language?

A low-level language is a programming language close to the instructions the CPU actually executes. Machine code and assembly language are low-level languages.

What is machine code?

Machine code is a set of binary instructions that the CPU can execute directly. Each family of processors has its own machine code.

What is assembly language?

Assembly language is a low-level language that uses short mnemonics such as ADD and STA. Each mnemonic stands for a single machine code instruction.

Why are high-level languages easier for programmers to use?

High-level code reads like English, so it is quicker to write, understand and debug. One high-level statement can do the work of many machine code instructions.

Why can a program written in a high-level language run on different types of processor?

High-level code is not tied to one processor's instruction set. The code can be translated into the machine code of whichever processor will run it.

OCR GCSE Computer Science J277

Systems Architecture

Topic overview CPU components and the fetch-execute cycle Factors affecting CPU performance Embedded systems

Memory and Storage

Topic overview RAM, ROM, cache and virtual memory Secondary storage: magnetic, optical and solid state Data units and storage capacity calculations Binary, denary and hexadecimal conversions Binary addition, overflow and binary shifts Character sets, ASCII and Unicode Bitmap images, colour depth and resolution Sound sampling, sample rate and bit depth Lossy and lossless compression

Computer Networks, Connections and Protocols

Topic overview LANs, WANs and network performance Client-server and peer-to-peer networks Network hardware, DNS, hosting and the cloud Star and mesh topologies Wired and wireless connections, IP and MAC addresses Protocols, standards and layers

Network Security

Topic overview Malware, social engineering and brute-force attacks Denial of service, data interception and SQL injection Identifying and preventing vulnerabilities

Systems Software

Topic overview User interfaces, memory management and multitasking Peripheral, user and file management Utility software

Ethical, Legal, Cultural and Environmental Impacts of Digital Technology

Topic overview Ethical and cultural issues in digital technology Environmental impact of digital technology Privacy and digital technology Computer Science legislation and software licences

Algorithms

Topic overview Abstraction, decomposition and algorithmic thinking Flowcharts, pseudocode and structure diagrams Trace tables and correcting algorithms Linear and binary search Bubble, merge and insertion sort

Programming Fundamentals

Topic overview Variables, constants, operators and assignment Sequence, selection and iteration Data types and casting String manipulation and file handling Arrays, records and SQL Functions, procedures and random numbers

Producing Robust Programs

Topic overview Defensive design, input validation and authentication Writing maintainable code Testing, errors and test data

Boolean Logic

Topic overview Logic gates and truth tables Combining gates in logic diagrams

Programming Languages and Integrated Development Environments

Topic overview High-level and low-level languages and translators The integrated development environment (IDE)

Programming Languages and Integrated Development Environments

High-level and low-level languages and translators

3 things to know
J277/02

Overview

High-level and low-level languages, machine code and assembly language, source code, and how compilers and interpreters differ in translation, speed and error reporting.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Process

Why are high-level languages easier to use and able to run on different processors?

Key term

What is source code, and why must it be translated before it runs?

Key term

What is a high-level language?

Questions from this subtopic

Each one with the model answer underneath.

1
What is a high-level language?
Model answer
A high-level language is a programming language that uses English-like keywords and familiar mathematical symbols. Python, Java and C# are examples.
2
What is a low-level language?
Model answer
A low-level language is a programming language close to the instructions the CPU actually executes. Machine code and assembly language are low-level languages.
3
What is machine code?
Model answer
Machine code is a set of binary instructions that the CPU can execute directly. Each family of processors has its own machine code.
4
What is assembly language?
Model answer
Assembly language is a low-level language that uses short mnemonics such as ADD and STA. Each mnemonic stands for a single machine code instruction.
5
Why are high-level languages easier for programmers to use?
Model answer
High-level code reads like English, so it is quicker to write, understand and debug. One high-level statement can do the work of many machine code instructions.
6
Why can a program written in a high-level language run on different types of processor?
Model answer
High-level code is not tied to one processor's instruction set. The code can be translated into the machine code of whichever processor will run it.

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