Architecture Basics

CSA Prelim

Data

A fact, figure, or information that is represented in a set of bits - ones and zeros. Wires and circuits bring forth these bits as electrical pulses in the computer system. These bits can be a file, information, or instruction.

File Type

It is a name given to a specific kind of file.

File Name

It is a unique file identifier and may be named by a human or a computer.

File Extension

It is a 1- to 4-letter character identifier for the specific file type.

File Extension Icon

It is a common identifier for file extension.

File Association

It is a program associated with the file extension.

File Format

It is a structure or layout of a computer file in terms of how data is contained and organized. The structure of a typical file may include a header, metadata, a saved content, and an end- of-file (EOF) marker. The data stored in the file depends on the purpose of the file format.

Metadata

It provides additional information about a certain item's content. The other terms for metadata are descriptions, keywords, tags. (Example: JPEG-dimensions, date created, date accessed, color depth, etc.)

File Attributes

These are settings associated with computer files that grant or deny certain rights to how a user or the operating system can access that file.

Read-only

It allows a file to be read, but nothing can be written to the file or changed.

Archive

It tells Windows Backup to back up the file.

System

It is a system file.

Hidden

It is a file that cannot be seen when doing a regular directory.

American Standard Code for Information Interchange (ASCII)

Originally developed as a standard by the American National Standards Institute (ANSI). ANSI has also defined 8-bit extensions to the original ASCII codes that provide various symbols, line shapes, and accented foreign letters for the additional 128 entries.

Extended Binary Coded Decimal Interchange Code

Developed by IBM. Its use is restricted mostly to IBM and IBM-compatible mainframe computers and terminals.

Unicode

Supports approximately a million characters, using a combination of 8-bit, 16-bit, and 32-bit words. It divides its character encodings into sixteen 16-bit code pages, called planes, which allows space for about a million characters.

Bitmap objects

Images (e. g., photographs and paintings) that are characterized using an image scanner, digital camera or mobile device, or video camera frame grabber.

Graphical objects

Images made up of graphical shapes (e. g., lines and curves) that can be defined geometrically.

Graphics Interchange Format (GIF)

First developed by CompuServe in 1987 as a proprietary format that would allow users to store and exchange online bitmap images in 256 colors on different computing platforms. Now, it is extensively used on the Web due to its animated frame-by-frame images.

Portable Network Graphics (PNG)

Best known compressed alternative to GIF. PNG can store up to 48 bits of color per pixel and can store a transparency percentage value and a correction factor for the color in a monitor or printer.

Joint Photographers Expert Group (JPEG)

Employs a compression algorithm to reduce the amount of data stored and transmitted. This algorithm reduces the image resolution under certain circumstances, particularly for sharp edges and lines, which makes JPEG more suitable for the representation of highly detailed photographs and paintings.

Video images

A a result of a sequence of bitmap image frames. The video format is determined by a codec or encoder/decoder algorithm referred to as a "container." The container serves as a superstructure to encode, decode, hold, and stream video. It serves both video and audio and may support multiple codecs.

Sampling

Lays out of the analog signal in a graph.

Quantization

Layers the discrete signal in the analog signal with less margin of error.

Encoding

Converts discrete signals into highs (1) and lows (0), hence the binary equivalent of a time- bound discrete signal.

Boolean

Constant values (true/false)

Char

Alphanumeric character code

Enumerated

User-defined data type

Integer

Whole numbers (+/-)

Real/Float

Numbers with a decimal portion

Lossless algorithm

Compresses the data in such a way that the application of a matching inverse algorithm restores the compressed data exactly to its original form.

Lossy algorithm

Operates on the assumption that the user can accept a certain amount of data degradation as a trade-off for the savings in a critical resource, such as storage requirements or data transmission time.