Explanation

• XLOOKUP replaces VLOOKUP and HLOOKUP.
• Works both horizontally and vertically
• Direct return range — no column number
• Built-in "not found" option
• No need for sorted data

Additional information:

• SUM and AVERAGE — These are aggregation functions, unrelated to lookups.
• COUNT and COUNTA — These count cells; not replaced by XLOOKUP.
• IF and AND — Logical functions, not lookup functions.

Last updated 07-09-2026 by NA

Explanation

• HTTPS (Hypertext Transfer Protocol Secure) uses Port 443 for secure communication
• It protects sensitive information like passwords, credit card numbers, and personal data from being stolen or read by attackers

Additional information

• Port 80 — standard HTTP (unencrypted web traffic)
• Port 21 — FTP (file transfer)
• Port 25 — SMTP (email sending)

Last updated 07-09-2026 by NA

Explanation

• 1 Petabyte (PB) is equivalent to 1,024 Terabytes (TB) in binary measurement and 1,000 Terabytes (TB) in decimal measurement
• Binary (Base-2, used by operating systems):
• 1 PB = 1,024 TB
• 1,048,576 GB (1,024 × 1,024 GB)
• Decimal (Base-10, used by storage manufacturers):
• 1 PB = 1,000 TB
• 1,000,000,000,000,000 bytes (10¹⁵ bytes) 

Last updated 07-09-2026 by NA

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