Computer Science key words week 2

Network Topology

Network Topology

The arrangement of elements in a communication network

FTP file transfer protocol

Used for sending files between computers, usually on a wide area network

Social engineering

Social engineering aims to manipulate people into giving away private information, such as passwords and PIN numbers.

Most vulnerabilities are caused by humans - not locking computers, using weak passwords, not following company network policy or implementing it poorly, not installing protection software, not being vigilant with suspicious emails/files and not encrypting sensitive data.

Abstraction

Abstraction is the process of filtering out characteristics of problems that are not needed in order to concentrate on those which are needed, thus allowing the programmer to focus on what the problem is and how to solve it.

Example: London Underground map

Data Type

The data type determines what type of value a variable will hold.

E.g. the string data type holds characters that can be letters and/or numbers

Selection

One of the three basic programming constructs. Instructions that can evaluate a Boolean expression and branch off to one or more alternative parts. Represented in Python with IF, ELIF and ELSE. In a flowchart represented by one or more decision diamonds.

Logic gate: AND

Accepts two inputs and produces one output. Both inputs must be TRUE (1) for the output to be TRUE (1) - otherwise, the output will be FALSE (0).

In a diagram this gate is a D shape.

Hexadecimal (base 16)

A numerical system of notation that uses 16 as its base rather than 10. The 16 hex base digits are 0-9 and the letters are A-F.

Denary—> Binary —> split into nibbles —> Hex

GB gigabyte

One gigabyte is 1000 megabytes - a powers-of-10 decimal prefix

RLE run length encoding

A simple form of lossless data compression where runs of data are stored as a single data value and count rather than a series of repeating, identical values. Most useful on data that contains large amounts of contiguous repeating data.

E.g AAABBBCCC could be coded as 3A3B3C