The compound noun "walkthrough" is a modern formation from the 20th century, built from the common English verb "walk" and the preposition "through." It literally evokes the image of guiding someone step-by-step through a process, as if walking them from the beginning to the end. The term gained specific prominence in computing and gaming, where it denotes a complete, guided demonstration of a software application or a path to victory in a game. This evolution from a literal physical action to a metaphorical guide for complex procedures demonstrates how English readily creates transparent, descriptive compounds for new technological and instructional concepts.

Structure: walk (move) + through (from one side to the other) - walk: From Old English wealcan (to roll, toss) and wealcian (to roll up, curl), via Middle English walken (to move about). Its functional role is the core verb meaning "to move at a regular pace." - through: From Old English þurh, from Proto-Germanic thurkh, related to the concept of penetration or completion from one end to another. Its functional role is a preposition/adverb indicating passage.