Karnataka KSEAB II PUC Information Technology (Vocational) flashcards

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

Volatile memory

Memory that loses its stored contents when electrical power is removed. RAM and cache are volatile; ROM, flash storage, and hard disks retain data without power.

Cache memory

A small, very fast memory between the CPU and RAM that holds recently used instructions and data. It reduces average access time because most requests are served without waiting for slower RAM.

BIOS and POST

Firmware stored on the motherboard that runs the Power-On Self-Test at startup, detects attached hardware, and then loads the bootloader so the operating system can start.

Impact versus non-impact printer

An impact printer strikes a ribbon against paper, so it can produce multi-part carbon copies but is noisy. Non-impact printers such as laser and inkjet use heat, pressure, or ink spray without striking.

Round Robin scheduling

A preemptive CPU scheduling algorithm that gives each ready process a fixed time quantum in turn. It guarantees fair response time but adds context-switch overhead if the quantum is too small.

Virtual memory

A technique where the operating system moves pages between RAM and disk so programs can exceed physical memory size. Excessive page swapping causes thrashing, which sharply reduces throughput.

Absolute versus relative path

An absolute path starts at the file system root, such as C:\Users\Me\notes.txt. A relative path is resolved from the current working directory, such as ..\notes.txt.

Disk defragmentation

A utility that rearranges fragmented file blocks on a mechanical hard disk into contiguous regions so read heads travel less. It should not be applied to SSDs, which have no moving parts.

Mail merge

A word-processing feature that combines one main document containing merge fields with a data source of records, producing a personalised copy of the document for every record.

Paragraph versus character formatting

Paragraph formatting such as alignment, indents, and line spacing applies to an entire paragraph. Character formatting such as font, size, bold, and colour applies only to selected text.

Table of contents generation

An automatic list of headings built by the word processor from text formatted with heading styles. It updates when headings change, unlike a manually typed list.

Absolute cell reference

A reference written with dollar signs, such as $B$4, whose row and column stay fixed when the formula is copied to another cell. A mixed reference fixes only one part.

VLOOKUP exact match

A spreadsheet function that searches the first column of a range for a value and returns a cell from a specified column. The fourth argument FALSE or 0 forces an exact match.

COUNT versus COUNTA

COUNT returns the number of cells containing numeric values. COUNTA returns the number of non-empty cells, including text and logical values, so it is larger when text is present.

Spreadsheet error value #DIV/0!

The error shown when a formula divides a number by zero or by an empty cell. It is prevented by testing the divisor with IF before performing the division.

Slide master

A presentation template layer that stores fonts, colours, background, and placeholder positions for a set of slide layouts. Editing it updates every slide that uses those layouts.

Transition versus animation

A transition is the visual effect between one slide and the next. An animation is an effect applied to an individual object inside a slide, such as text or a picture.

Raster versus vector graphics

Raster images such as JPEG and PNG store a grid of pixels and blur when enlarged. Vector graphics store mathematical shapes and scale without loss of quality.

Speaker notes

Text attached to a slide that is visible to the presenter in Presenter View and on printed notes pages but is not shown to the audience during a slide show.

Primary key

An attribute or minimal set of attributes that uniquely identifies each row of a table. It must be unique and cannot contain a null value.

Foreign key

An attribute in one table that references the primary key of another table. It enforces referential integrity, so a row cannot point to a parent record that does not exist.

Third normal form

A table is in 3NF when it is already in 2NF and no non-key attribute depends transitively on another non-key attribute. This removes redundancy and update anomalies.

WHERE versus HAVING

WHERE filters individual rows before grouping and cannot use aggregate functions. HAVING filters groups after GROUP BY and can test aggregates such as COUNT or SUM.

Post-test loop

An iteration structure that tests its condition after executing the loop body, so the body runs at least once. Examples are do-while and repeat-until.

Binary search precondition

The data must already be sorted before a binary search is applied. The algorithm compares the target with the middle element and discards half the remaining range each step.

Pass by reference

A parameter-passing method where the function receives the memory address of the argument, so changes made inside the function affect the caller's original variable.

CSS specificity

The rule that decides which conflicting style wins. Inline styles outrank id selectors, which outrank class selectors, which outrank element selectors, when declarations target the same element.

HTTP status code 404

The response code meaning the server was reached but no resource exists at the requested URL. It differs from 500, which indicates a server-side failure.

DNS resolution

The process of translating a human-readable domain name such as example.com into the numeric IP address that routers use to deliver packets to the correct server.

Star topology

A network layout in which every device connects to a central hub or switch. Failure of one cable affects only that device, but failure of the centre disables the whole network.

TCP versus UDP

TCP is connection-oriented, acknowledges segments, and retransmits lost data, so it is reliable but slower. UDP is connectionless with no acknowledgement, giving low latency for streaming.

Ransomware

Malicious software that encrypts a victim's files or locks the system and demands payment for the decryption key. Regular offline backups are the main defence against data loss.