A-Level Computer Science - AQA
2023 Flashcard
Laser Printer - -answer-A type of printer that uses electrical charges to create an image on
paper. The printer drum and the toner are negatively charged, and the charge on the drum
is neutralised in certain areas with a laser, making the toner stick to the drum in these
places. The paper passes over the drum and the toner is transferred with the help of a
positively charged roller, and the toner is then fused with the paper using heat. Colour
printers repeat this process over four drums, one for each toner colour.
Hard Drives - -answer-A non-volatile, magnetic form of internal or external storage, that
permanently stores and retrieves data on a computer
Solid State Drive (SSD) - -answer-Secondary storage consisting of many transistors that
store a bit of data in the form of electrical charge, even when unpowered. As data is stored
electronically, there are no moving parts.
Optical Disk - -answer-A form of secondary storage that uses light emitted by a laser to
read and write onto a disk.
Encapsulation - -answer-Combining attributes and methods together into an object
Normalisation - -answer-The process of decomposing a flat-file into the best possible design
for a relational database, making it less likely to lose data, create inconsistencies, or create
redundant data
Encryption - -answer-Using an algorithm to change data so that it can only be read by the
intended recipient
,Cipher - -answer-The algorithm which is used to encrypt or decrypt data
Symmetric Encryption - -answer-The same key is used to both encrypt and decrypt the data
Asymmetric Encryption - -answer-A device has a public key and a private key. The keys are
linked such that a message encrypted by the public key can only be decrypted by the private
key. A message is encrypted with the recipient's public key, and then decrypted by the
recipient with their private key
Machine Code - -answer-Code written in binary which can be read by the computer
Instruction Set - -answer-All of the different possible instructions the computer can carry
out
Operation Code (Opcode) - -answer-Part of the binary code which tells us what operation is
being carried out
Operand - -answer-Part of the binary code which tells us what to carry out the instruction
on
Assembly Code - -answer-Machine code that can easily be read by humans
Assembler - -answer-Converts assembly language into machine code that the computer can
run
Source Code - -answer-The code that will be translated by the compiler/interpreter
Interpreter - -answer-Translates code from a high level language to computer hardware.
Code is run after each line is translated, so it doesn't create 1 piece of machine code
Compiler - -answer-Translates from high level language to machine code, to computer
hardware. A one off translation from source code to machine code
Object Code - -answer-The translated code produced by a compiler/interpreter
, Hypertext Transfer Protocol (HTTP) - -answer-Port 80 - used for viewing web pages
Hypertext Transfer Protocol Secure (HTTPS) - -answer-Port 443 - used for accessing
secure web pages
Secure Shell (SSH) - -answer-Port 22 - used for remotely accessing and managing a
computer. Uses public key encryption
Post Office Protocol (POP3) - -answer-Port 110 - used for downloading personal emails from
a web sever
Simple Mail Transfer Protocol (SMTP) - -answer-Port 25 - used for sending email messages
File Transfer Protocol (FTP) - -answer-Port 21 - used for uploading files to a web server
Natural Numbers - -answer-Positive integers
Integers - -answer-Whole numbers, positive or negative
Rational Number - -answer-Any number that can be expressed as a ratio of two numbers
e.g. 2/3
Irrational Numbers - -answer-A real number that cannot be expressed as a ratio of two
numbers e.g. pi or e
Real Number - -answer-Any positive or negative number, including integers, rational and
irrational numbers
Ordinal Number - -answer-A number that refers to the position of an item in a set, e.g. 1st,
2nd, 3rd
Cardinal Numbers - -answer-A number that refers to the count of something, e.g. 1,2,3,4
2023 Flashcard
Laser Printer - -answer-A type of printer that uses electrical charges to create an image on
paper. The printer drum and the toner are negatively charged, and the charge on the drum
is neutralised in certain areas with a laser, making the toner stick to the drum in these
places. The paper passes over the drum and the toner is transferred with the help of a
positively charged roller, and the toner is then fused with the paper using heat. Colour
printers repeat this process over four drums, one for each toner colour.
Hard Drives - -answer-A non-volatile, magnetic form of internal or external storage, that
permanently stores and retrieves data on a computer
Solid State Drive (SSD) - -answer-Secondary storage consisting of many transistors that
store a bit of data in the form of electrical charge, even when unpowered. As data is stored
electronically, there are no moving parts.
Optical Disk - -answer-A form of secondary storage that uses light emitted by a laser to
read and write onto a disk.
Encapsulation - -answer-Combining attributes and methods together into an object
Normalisation - -answer-The process of decomposing a flat-file into the best possible design
for a relational database, making it less likely to lose data, create inconsistencies, or create
redundant data
Encryption - -answer-Using an algorithm to change data so that it can only be read by the
intended recipient
,Cipher - -answer-The algorithm which is used to encrypt or decrypt data
Symmetric Encryption - -answer-The same key is used to both encrypt and decrypt the data
Asymmetric Encryption - -answer-A device has a public key and a private key. The keys are
linked such that a message encrypted by the public key can only be decrypted by the private
key. A message is encrypted with the recipient's public key, and then decrypted by the
recipient with their private key
Machine Code - -answer-Code written in binary which can be read by the computer
Instruction Set - -answer-All of the different possible instructions the computer can carry
out
Operation Code (Opcode) - -answer-Part of the binary code which tells us what operation is
being carried out
Operand - -answer-Part of the binary code which tells us what to carry out the instruction
on
Assembly Code - -answer-Machine code that can easily be read by humans
Assembler - -answer-Converts assembly language into machine code that the computer can
run
Source Code - -answer-The code that will be translated by the compiler/interpreter
Interpreter - -answer-Translates code from a high level language to computer hardware.
Code is run after each line is translated, so it doesn't create 1 piece of machine code
Compiler - -answer-Translates from high level language to machine code, to computer
hardware. A one off translation from source code to machine code
Object Code - -answer-The translated code produced by a compiler/interpreter
, Hypertext Transfer Protocol (HTTP) - -answer-Port 80 - used for viewing web pages
Hypertext Transfer Protocol Secure (HTTPS) - -answer-Port 443 - used for accessing
secure web pages
Secure Shell (SSH) - -answer-Port 22 - used for remotely accessing and managing a
computer. Uses public key encryption
Post Office Protocol (POP3) - -answer-Port 110 - used for downloading personal emails from
a web sever
Simple Mail Transfer Protocol (SMTP) - -answer-Port 25 - used for sending email messages
File Transfer Protocol (FTP) - -answer-Port 21 - used for uploading files to a web server
Natural Numbers - -answer-Positive integers
Integers - -answer-Whole numbers, positive or negative
Rational Number - -answer-Any number that can be expressed as a ratio of two numbers
e.g. 2/3
Irrational Numbers - -answer-A real number that cannot be expressed as a ratio of two
numbers e.g. pi or e
Real Number - -answer-Any positive or negative number, including integers, rational and
irrational numbers
Ordinal Number - -answer-A number that refers to the position of an item in a set, e.g. 1st,
2nd, 3rd
Cardinal Numbers - -answer-A number that refers to the count of something, e.g. 1,2,3,4
