Glossary | UtilityForge

Aspect ratio: The proportional relationship between width and height, written like 16:9.
Broadcast address: The last address in an IPv4 subnet, used to reach every host in it. Not assignable to a device in ordinary subnets.
Business day: A day on which offices are normally open, excluding weekends and public holidays as defined by the relevant agreement.
Campaign (UTM): The utm_campaign value naming a specific promotion or push, such as diwali_offer.
chmod: Command that changes the permissions of a file or directory.
chown: Command that changes the owner and group of a file or directory.
CIDR: Classless Inter-Domain Routing. A notation like 10.0.0.0/22 where the number after the slash says how many leading bits identify the network.
CLS: Cumulative Layout Shift. A Core Web Vitals metric measuring how much visible content moves unexpectedly while a page loads.
Contrast ratio: A number from 1:1 to 21:1 describing the brightness difference between two colours.
Cron: A time-based job scheduler on Unix-like systems.
crontab: The file (and command) that holds a user's cron schedule.
Daylight saving time: The seasonal shifting of clocks by an hour in some countries. India does not use it.
Diff: A comparison of two texts that lists what was added and removed.
EMI: Equated Monthly Instalment. The fixed payment on a loan covering interest and some principal.
Epoch: The reference moment, 1 January 1970 UTC, from which Unix timestamps count seconds.
Execute bit: The permission that lets a file be run as a program or lets a directory be entered.
Host bits: In an IPv4 address, the trailing bits not fixed by the prefix. They number 32 minus the prefix length.
IANA time zone database: The shared database of time-zone rules that operating systems and browsers use.
Keyword stuffing: Repeating a word or phrase so often that text reads unnaturally, which search engines treat as spam.
Large text (WCAG): Text of at least 24px, or 18.7px and bold, which has a lower contrast requirement.
Line-based diff: A comparison that treats each line as a unit, so a changed word marks the whole line as changed.
Medium (UTM): The utm_medium value naming the channel type, such as email or cpc.
Network address: The first address in a subnet, with all host bits zero.
Octal: Base-8 numbers. Permissions such as 755 are written in octal.
Octet: One of the four 8-bit groups of an IPv4 address, each from 0 to 255.
Prepayment: Paying part of a loan's principal ahead of schedule.
Prefix length: The number after the slash in CIDR notation.
Principal: The amount of money borrowed, excluding interest.
Private address range: Addresses reserved for internal networks: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.
Reducing-balance loan: A loan where interest is charged on the outstanding balance, which falls over time.
Relative luminance: A measure of how bright a colour appears to the human eye, used in WCAG contrast maths.
Setgid: A permission bit that makes new files in a directory inherit the directory's group.
Source (UTM): The utm_source value naming where traffic comes from, such as newsletter.
Stop words: Very common words like the, and, of, often ignored in word-frequency analysis.
Subnet mask: A 32-bit value that separates the network part of an address from the host part, e.g. 255.255.255.0.
Tenure: The length of a loan, usually in months or years.
umask: A setting that removes permission bits from the defaults applied to newly created files and directories.
UTC: Coordinated Universal Time, the reference for civil time. Offsets such as +5:30 are measured from it.
UTM parameters: Tags appended to a URL so analytics tools can attribute a visit to a source, medium and campaign.
WCAG: Web Content Accessibility Guidelines, the international standard for accessible web content.
Wildcard mask: The bitwise inverse of a subnet mask, used in some router access lists.