2.2 Applications Generation (OCR A Level Computer Science) Flashcards

Disk defragmentation is a utility that rearranges files on a hard drive into contiguous blocks to increase efficiency and speed up file access.

A device driver provides an interface between the hardware and the operating system.

False.

Modern SSDs do not require disk defragmentation, as it does not improve their performance.

A system cleanup utility removes unnecessary files and data from a computer, such as temporary files and system cache, to free up space and improve performance.

File management utilities allow users to organise, search, rename, and relocate files and folders.

Security utility software protects the computer from threats such as viruses, malware, and spyware, monitoring and controlling activities to keep the system safe.

Open source software is software where the source code is made freely available, and can be viewed, modified, and redistributed by anyone.

Closed source software is software where the source code is kept secret and proprietary, so only the creators can view, modify, or distribute it.

A benefit to the user of using open source software is that it is often free, customisable, and transparent.

A drawback to the creator of open source software is having less control over the software and potentially being burdened with many user requests.

In closed source software, the source code is kept secret and cannot be modified by users.

True.

Open source software is designed to allow anyone to view, modify, and share the code, supporting collaboration and transparency.

Linux and Apache HTTP Server are examples of open source software.

A benefit to a business of using closed source software is that it is typically well-polished, professionally supported, and helps protect intellectual property.

A translator is a program that converts source code from a high-level language into a low-level language.

A compiler translates the entire source code into machine code at once, while an interpreter translates and executes source code line-by-line.

An assembler is a translator that converts assembly language into machine code.

An interpreter translates source code line-by-line and executes it directly.

True.

Compiled programs are converted into machine code all at once, resulting in faster execution than programs interpreted line-by-line.

A assembler is needed to translate assembly language into machine code.

High-level languages like Python are often interpreted to provide greater portability and flexibility, allowing the same code to run on different platforms.

Compiled languages like C enforce stricter type-checking at compile time.

Compilation is the process of translating a program written in a high-level programming language into machine code, which can be executed by a computer.

The four stages of compilation are: Lexical Analysis, Syntax Analysis, Code Generation and Optimisation.

Lexical analysis is the stage of compilation that breaks source code into tokens, identifying keywords, identifiers, operators, and separators, while ignoring whitespace and comments.

The lexical analysis stage produces a token table, which lists all identified tokens and their types for use in later compilation stages.

Three types of tokens identified during lexical analysis are keywords, identifiers, and operators.

An Abstract Syntax Tree (AST) is a graph-based representation of the structure of source code, created during syntax analysis to facilitate further stages of compilation.

True.

During lexical analysis, unnecessary elements like comments and whitespace are ignored when breaking code into tokens.

In syntax analysis, the compiler checks that tokens adhere to the syntax rules of the programming language.

If a program contains mismatched parentheses, this will be flagged as a syntax error during syntax analysis.

The purpose of the optimisation stage is to make the generated code more efficient without changing its functionality, often by removing duplicate code or reducing memory usage.

A code library is a collection of pre-written code, classes, or procedures that developers can include in their programs to perform common tasks without writing code from scratch.

An example is the JavaScript library Lodash, which provides utility functions for working with arrays and objects, saving developers time and effort when manipulating data.

Using a library can save time and effort for developers because common tasks do not need to be written from scratch.

One advantage of using library files is that they provide pre-tested, reliable code, which saves development time and reduces the chance of introducing errors.

One disadvantage of using library files is that they can introduce unnecessary complexity or dependency issues, especially if the library is large or becomes unsupported.

Most programming languages come with standard libraries, which offer basic functionalities.

A linker is a program that combines object files and libraries into a single executable, resolving references between them during the compilation process.

False.

A linker is responsible for linking code files, while a loader loads the executable into memory for execution.