Derived from "foo" and "bar," it originated in the 1940s from military slang "FUBAR" ("Fouled Up Beyond All Recognition").

Programmers adopted these terms as generic variables or placeholders.

Popularized by the 1978 book The C Programming Language by Brian Kernighan and Dennis Ritchie, it is often used as the first program to demonstrate basic syntax in a new language.

A placeholder text used in design and typesetting to simulate the layout of a page before the actual content is available. It’s derived from a scrambled passage of Latin from Cicero's works.

It comes from a famous 1970 Monty Python comedy sketch, where a group of Vikings repeatedly sings the word "spam" (referring to the canned meat product) in a restaurant.

The relentless, repetitive nature of the chant mirrors the overwhelming and unwanted presence of spam emails.

The term "bug" for a software defect dates back to a famous incident in 1947, when computer pioneer Grace Hopper discovered a moth causing a malfunction in an early computer.

Although "bug" had been used to describe mechanical malfunctions before this, the story of the moth getting stuck in the hardware became part of computing folklore, solidifying the term.

In web development, a "cookie" is a small piece of data stored on a user's device to track and identify them.

The name likely comes from the concept of "fortune cookies," which were tokens used in early computer systems and inspired by fortune cookies, where hidden data is "wrapped" inside.

In security and software development, a "sandbox" is an isolated environment where programs can be tested safely without affecting the broader system.

The term comes from children's play areas where sandboxes provide a controlled space for play, similar to how this concept protects the system from potentially harmful activities.

In file systems, the "root" is the top-most directory from which all other directories branch.

This term comes from botany, where a tree's root is the foundation from which everything grows, symbolizing the hierarchical structure of directories.

In programming, particularly in the context of APIs and malware, "payload" refers to the actual data or malicious code delivered by a system or virus.

The term comes from the aerospace industry, where "payload" refers to the cargo carried by a vehicle, especially in space missions.

In computing, "NaN" is used to represent a value that is undefined or unrepresentable, like dividing zero by zero.

The concept comes from mathematical notation, where operations that don’t yield a valid number are marked as undefined.