Guides & how-tos
Short, practical articles that go deeper than a tool page: how things work, what the limits are, and how professionals approach the task.
· 9 min read
chmod 755 vs 644 vs 777: What the Numbers Mean
chmod 755 is rwxr-xr-x and 644 is rw-r--r--, differing only by the execute bit. See how each digit is computed, which to use where, and why 777 is wrong.
#chmod #linux #file-permissions #octal #sysadmin
· 9 min read
Hourly to Annual Salary: The 2,080-Hour Formula
Hourly to annual salary: multiply your wage by 2,080 (40 hours × 52 weeks). See worked examples, why real pay differs, the federal 2,087 rule and the reverse.
#hourly-wage #annual-salary #2080-hours #gross-pay #pay-conversion
· 9 min read
How Long Should a Password Be? What NIST Says
NIST's 2025 guidance sets 15 characters as the minimum when a password stands alone and 8 with a second factor. See the entropy math, passphrase lengths, myths.
#password #nist #passphrase #entropy #account-security
· 9 min read
How Many Words Is a 10 Minute Speech? Plus 5 and 20
A 10 minute speech is about 1,500 words at 150 words per minute, or 1,300 to 1,800 at slow and fast paces. See 5 and 20 minute counts and what pauses change.
#speech-length #speaking-time #words-per-minute #presentations
· 9 min read
How Much Do YouTubers Make? RPM, CPM and Payouts
How much do YouTubers make? Ad income is views divided by 1,000 times RPM, often quoted at $2 to $10. See the math, a range table and Partner Program rules.
#youtube-earnings #rpm #cpm #partner-program #creator-income
· 9 min read
Invisible Characters in Text: Causes and Fixes
Invisible characters in text, such as zero-width and non-breaking spaces, arrive through copy-paste and make matching fail. Learn to find and remove each one.
#invisible-characters #unicode #zero-width-space #data-cleaning #copy-paste
· 9 min read
Meta Description Length: How Long Should It Be?
Google sets no fixed meta description length. Snippets are cut to fit the screen, roughly 920 px on desktop, and are often rewritten. See what to aim for.
#meta-description #on-page-seo #serp-snippets #pixel-width
· 9 min read
Percentage Change vs Percentage Points Explained
A percentage point is the gap between two percentages; percentage change divides that gap by the start. Worked examples with rates, polls and conversions.
#percentages #percentage-points #percent-change #statistics #reporting
· 9 min read
UUID v4 vs v7: Which Should You Use?
UUID v7 sorts by time and suits database primary keys; UUID v4 is fully random and reveals nothing. Compare bit layouts, index effects and when to pick each.
#uuid #database #primary-key #rfc-9562 #identifiers
· 9 min read
WebP vs PNG vs JPG: Which Image Format Should You Use?
WebP vs PNG vs JPG: use JPG for photos that must open anywhere, PNG for text and edits, WebP for smaller web files. Backed by measured byte sizes.
#webp #png #jpg #image-formats #web-performance