Explanation

• The primary function of a Subnet Mask in IPv4 networking is to distinguish the Network ID from the host ID
•  It splits the 32-bit IPv4 address into two distinct parts.
• Uses bitwise AND with the IP address to separate the network and host portions
• Not for: MAC addressing (ARP), encryption (IPsec/TLS), auto-assignment (DHCP)

Last updated 07-09-2026 by NA

Explanation

• The formula =COUNTA(A1:A5) counts Non-empty cells (text & numbers).
• The function counts cells containing any type of data, including:
• Numbers
• Text or letters
• Logical values (TRUE or FALSE)
• Error values (like #N/A or #REF!)
• Empty text strings (such as "" returned by a formula)

Additional information:

• COUNT counts only cells with numbers
• COUNTIF/COUNTIFS count cells meeting specific criteria
• COUNTBLANK counts empty cells

Last updated 07-09-2026 by NA

Explanation

• Cache Memory — the buffer between CPU and RAM.

  • Stores frequently used data for quick CPU access
  • Faster but smaller than RAM
  • Falls between the CPU and main memory
  • Has levels (L1, L2, L3) — L1 is fastest/closest to CPU
  • Reduces memory access time, boosting performance

Additional information:

• RAM = the main memory itself
• ROM = read-only, holds firmware (BIOS)
• SRAM = a type used to build cache, not the buffer itself

Last updated 07-09-2026 by NA

Explanation

•  SFC /scannow — it scans and repairs corrupted Windows system files.

Additional information:

• CHKDSK: checks disks for errors, not system files
• DISKPART: manages disk partitions
• TASKLIST: lists running processes

Last updated 07-09-2026 by NA

Explanation

• WPA3 is the latest, most secure Wi-Fi standard (2018).
• Uses SAE — blocks offline password-guessing attacks.
• Provides forward secrecy and stronger encryption.

Additional information:

• WEP — obsolete, easily cracked.
• WPA — older, uses TKIP, considered insecure.
• WPS — not an encryption standard, just a setup feature with known flaws.

Last updated 07-09-2026 by NA

Explanation

• BCC stands for Blind Carbon Copy.
• When you put an email address in the BCC field, that person receives the message.
• The people in the "To" and "CC" fields cannot see that the BCC recipient received a copy.
• It keeps the email addresses of the BCC recipients private from everyone else on the email.

Last updated 07-09-2026 by NA

Explanation

There are 3 main types of loops in C++:

1. For Loop  (including the modern range-based for loop)
2. While loop: repeats a statement or group of statements
3. do-while loop: Like a while loop, except that it tests the condition at the end of the loop body

Last updated 07-09-2026 by NA

Explanation

• In C++, the extraction operator (>>) is used to take input from the user.
• It is used in combination with the cin (character input) stream object, which belongs to the standard <iostream> library.

Last updated 07-09-2026 by NA

Explanation

• In C++, the cout object combined with the insertion operator (<<) is the standard way to display output on the screen.
• It is part of the std namespace and requires including the  <iostream> library

Last updated 07-09-2026 by NA

Explanation

• Slide animation is mainly used in presentation software like Microsoft PowerPoint
• To add visual motion effects to objects
• Apply movement to text, shapes, pictures, and charts on a single slide.

Last updated 07-09-2026 by NA