WBCHSE HS Modern Computer Application flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Von Neumann architecture

A design in which program instructions and data share the same main memory, and the CPU repeatedly fetches, decodes, and executes instructions.

CPU

The central processing unit executes instructions; it contains the arithmetic logic unit, control unit, and registers, and is often called the brain of the computer.

Cache memory

A small, fast volatile memory between the CPU and main memory that stores frequently used instructions and data to reduce average access time.

Primary versus secondary memory

Primary memory is directly accessed by the CPU and is usually volatile, while secondary memory is non-volatile storage such as hard disks and SSDs used for permanent data.

Positional number system

A number system in which a digit's value depends on its position, calculated as digit multiplied by the base raised to the position index.

Two's complement

A signed binary representation formed by inverting all bits of a number and adding one; an n-bit value ranges from -2^(n-1) to 2^(n-1)-1.

De Morgan's laws

Boolean identities stating that the complement of A OR B equals A-complement AND B-complement, and the complement of A AND B equals A-complement OR B-complement.

XOR gate

A logic gate whose output is 1 when exactly one input is 1; its Boolean expression is A'B + AB', and it gives 0 for equal inputs.

Operating system

System software that manages hardware, memory, files, processes, and input/output devices, and provides services and an interface for application programs and users.

Process states

A process commonly moves among new, ready, running, waiting, and terminated states as the operating system schedules CPU time and handles input or output events.

Virtual memory

A technique that uses secondary storage to extend apparent main memory, moving inactive pages to disk and loading them back when needed.

Paging

A memory-management scheme that divides logical memory into fixed-size pages and physical memory into frames, mapping pages to frames through a page table.

C format specifier

A conversion code in scanf or printf that tells the function how to read or display a value, such as %d for int and %f for float.

Null character in C

The character with numeric value zero, written as a backslash followed by zero, used to mark the end of a C string; string functions rely on it.

Pass by value

A function call method in C where the called function receives copies of argument values, so changes to parameters do not alter the caller's original variables.

C pointer

A variable that stores the memory address of another variable; the & operator obtains an address and * dereferences a pointer to access the stored value.

Stack

A linear data structure following last-in-first-out order, where insertion and deletion occur at the top and are called push and pop.

Queue

A linear data structure following first-in-first-out order, where insertion occurs at the rear and deletion at the front.

Binary search

A search algorithm that repeatedly halves a sorted array by comparing the target with the middle element, running in O(log n) time.

Inorder traversal

A binary-tree traversal that visits the left subtree, then the root, then the right subtree; on a binary search tree it produces sorted order.

Primary key

A column or set of columns that uniquely identifies each row in a table; it cannot contain NULL values and only one primary key is allowed per table.

Foreign key

A column or set of columns in one table that references a candidate key, usually the primary key, of another table to enforce referential integrity.

SQL aggregate function

A function such as COUNT, SUM, AVG, MIN, or MAX that computes a single value from many rows, often after grouping by a column.

Third normal form

A relation is in 3NF when it is in 2NF and every non-key attribute depends only on candidate keys, with no transitive dependency on non-key attributes.

IPv4 address

A 32-bit logical address written as four decimal octets separated by dots, uniquely identifying a network interface on an IPv4 network.

DNS

The Domain Name System translates human-readable domain names into IP addresses so clients can locate servers on the Internet.

TCP versus UDP

TCP provides reliable, ordered, connection-oriented delivery with acknowledgements, while UDP is connectionless, faster, and does not guarantee delivery or ordering.

Router

A network device that forwards packets between different networks by choosing paths from a routing table based on destination IP addresses.

HTML

HyperText Markup Language, the standard language for creating web page structure using elements marked by tags such as headings, paragraphs, and links.

CSS box model

A model describing each element as content surrounded by padding, border, and margin; total width includes content width plus padding and border.

Raster versus vector graphics

Raster images store a grid of pixels and lose quality when enlarged, while vector images use mathematical paths and scale without pixelation.

JPEG

A common lossy image format suited to photographs, which reduces file size by discarding some visual detail and does not support transparency.