TECHNOLOGY 

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KembaraXtra – Computer Terms – : means:
The colon symbol is used in many contexts. In URLs, it separates the protocol (like http or ftp) from the following parts of the address. In DOS file systems, it’s also used after the drive letter to indicate which disk is being referenced, such as C: for the main hard drive.


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KembaraXtra – Computer Terms – // means:
Two forward slashes appear in web addresses (URLs) directly after the protocol name (like http: or ftp:). They act as separators between the protocol and the web domain. For instance, in http://example.com, the // follows http: and comes before the domain name.


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KembaraXtra – Computer Terms – 0.07-micron means:
This refers to a semiconductor manufacturing process where features on a chip are only 0.07 microns wide—extremely small compared to the width of a human hair. This allows manufacturers to fit around 400 million transistors on a single chip. It leads to high-speed, high-performance processors that can exceed 10 GHz in speed. Applications include powerful computers, ultra-fast hard drives, and even medical devices like implanted hearing aids.


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KembaraXtra – Computer Terms – \ means:
The backslash is a directory path separator used in Windows and MS-DOS systems. Unlike UNIX, which uses forward slashes, Windows uses backslashes in file paths—for example, C:\Program Files\. When placed at the beginning of a path, it means that the path begins from the root of the disk.


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KembaraXtra – Computer Terms – @ means:
This symbol is central to email communication. It separates the username from the domain name in an email address. For example, in user@example.com, the @ reads as “at” and indicates that the user is associated with the example.com domain. It’s also used in other Internet services and authentication formats.


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KembaraXtra – Computer Terms – ? means:
The question mark is a wildcard character used in operating systems like MS-DOS, Windows NT, and OS/2. It stands in for any single character in a filename or search pattern. For example, file?.txt could match file1.txt or fileA.txt, but not file10.txt because it only replaces one character at a time.


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KembaraXtra – Computer Terms – > means:
The right angle bracket is commonly used in command-line interfaces to redirect output from a command into a file instead of displaying it on the screen. For example, echo Hello > file.txt will write “Hello” into a file. In emails, this symbol is used to indicate quoted or previously sent text.


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KembaraXtra – Computer Terms – / means:
The forward slash is used in UNIX and web-based systems to separate parts of a file path or a web address. For example, /home/user/documents is a typical path in UNIX. It’s also used in FTP paths and URLs. In command-line operations, it acts as a prefix to options or parameters that modify how a command runs, such as /p for pause or /s for recursive directory operations.


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KembaraXtra - Computer Science - Prefixes in Computing

1. Introduction to Prefixes

  • Purpose: Prefixes are used to represent large quantities of data (bits and bytes) in a concise and understandable way.
  • SI Prefixes (Metric System): A standardized system of prefixes used to quantify various measurements, including data sizes.

2. Common SI Prefixes (Base 10)

Prefix Name Prefix Symbol Value Base 10 English Word
tera T 1,000,000,000,000 10¹² trillion
giga G 1,000,000,000 10⁹ billion
mega M 1,000,000 10⁶ million
kilo k 1,000 10³ thousand
centi c 0.01 10⁻² hundredth
milli m 0.001 10⁻³ thousandth
micro μ 0.000001 10⁻⁶ millionth
nano n 0.000000001 10⁻⁹ billionth
pico p 0.000000000001 10⁻¹² trillionth
  • Usage: 3 billion bytes = 3GB; 4 thousand bits = 4kb
  • Case Sensitivity: 'B' = Byte, 'b' = bit

3. Base 2 vs. Base 10 in Computing

  • Bytes and Base 2: Computers internally operate in base 2 (binary).
  • "1MB" Misconception: A file labeled as "1MB" is often 1,048,576 bytes (2²⁰), not exactly 1,000,000 bytes.

4. SI Prefix Meaning When Applied to Bytes (Base 2)

Prefix Name Prefix Symbol Value Base 2
tera T 1,099,511,627,776 2⁴⁰
giga G 1,073,741,824 2³⁰
mega M 1,048,576 2²⁰
kilo k 1,024 2¹⁰

5. Network Transfer Rates

  • Advertisements: Internet speed is advertised in bits per second (base 10).
  • Conversion: To find the equivalent in bytes per second, divide the advertised speed by 8 (bits per byte).
  • Example: 50 Mbps internet = 50,000,000 bits/second = 6,250,000 bytes/second ≈ 6 MB/second.

6. IEEE 1541-2002 Prefixes for Binary Data

  • Purpose: Introduced to remove ambiguity between base 10 and base 2 interpretations of SI prefixes.
  • New Prefixes: kibi (Ki), mebi (Mi), gibi (Gi), tebi (Ti) are used to explicitly indicate powers of 2.
  • Intended Usage:
    • "kilobyte" (kB) should mean 1,000 bytes (base 10).
    • "kibibyte" (KiB) should mean 1,024 bytes (base 2).

7. IEEE 1541-2002 Prefixes Table

Prefix Name Prefix Symbol Value Base 2
tebi Ti 1,099,511,627,776 2⁴⁰
gibi Gi 1,073,741,824 2³⁰
mebi Mi 1,048,576 2²⁰
kibi Ki 1,024 2¹⁰

8. Practical Implications and Common Misunderstandings

  • Software Display: Most software uses the old SI prefixes (KB, MB, GB) but calculates sizes in base 2.
  • Storage Device Marketing: Manufacturers advertise storage capacity using base 10.
  • A "1TB" hard drive (1,000,000,000,000 bytes) will appear as roughly "931GB" when connected to a computer (1,000,000,000,000 bytes / 2³⁰).
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