Flashcards
AQA Computer Science A level
Cards in this deck (12)
- 1What are the types of software?Application software and system software. System software is divided into utility programs, library programs, translators and operating system software
- 2Give an example of a utility programCompression software, ant-virus software, back-up software and registry cleaners
- 3What does the OS do?Provides a virtual machine, manages users on a network, manages memory and processing time, manages I/O devices
- 4What is virtual memory?When secondary storage is used to store some code and files that are usually stored in RAM and the operating system uses it as if it were RAM. This allows more programs to be run simultaneously. Volatile and slower than RAM.
- 5What is paging?An alternative to virtual memory. A central block of code is held in RAM and other sections of code known as 'pages' are loaded from secondary storage when they are needed
- 6What is the difference between imperative and declarative languages?Imperative/Procedural - describes a sequence of steps telling the computer exactly what to do
Declarative - tells the computer what to do without specifying the control flow of exactly how to do it - 7FTP?File Transfer Protocol (port 21): Relates to copying a file from one computer to another over the internet. Can be anonymous or non-anonymous (protected) in which case a username and password is required.
- 8SSH?Secure Shell Protocol (port 22): Used to connect to a remote computer securely. Uses public key encryption on the data, username and password are required, uses a command line interface, creates a secure network of nodes.
- 9SSH commands?cd /windows/programfiles = change to this directory
rm essay.doc = delete file
mv essay.doc essay2.doc = rename essay.doc to essay2.doc
vi essay.doc = create a file named essay.doc - 10Telnet?Used to access remote computers over the internet (or manage a server?)
Port 23 - 11SMTPSimple Mail Transfer Protocol (ports 25 and 587): Used to send emails. Uses a series of SMTP servers which store email addresses of senders and recipients. Uses DNS servers to get IP addresses. If not sent data is put in a queue. Server attempts to send a set number of times.
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- Studying for GCSE Computer Science Flashcards on AQA Computer Science A level, created by Melissa Quail on 30/04/2018.
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- Melissa Quail
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