Undo
Overview
'되돌릴' is an inflected form of the Korean verb '되돌리다' (to turn back), meaning to return an object or state to its previous form. In information technology, this is implemented as the Undo function, allowing users to cancel an action they have performed and restore the immediately preceding state. Undo goes beyond a simple convenience feature; as a representative example of a 'forgiving interface' that permits user mistakes, it has become one of the basic principles of modern software design.
Key details
Linguistic and conceptual meaning
'되돌릴' originally meant physical reversal of direction, but in modern times it has expanded to the abstract meaning of temporal or logical restoration. As in the expression 'irreversible decision,' the distinction between what can and cannot be undone becomes an important criterion for gauging the extent of responsibility and risk.
Undo in computing
The undo function, which began with editors at Xerox PARC in the 1970s, later became standard in almost all applications. It is generally invoked with the Ctrl+Z (Windows/Linux) or Command+Z (Mac) shortcut, and internally stores state history through the Command Pattern or snapshot/journaling techniques. The opposite concept of undo is redo, and most editors provide the two functions as a pair. Supporting unlimited levels of undo requires designing a balance between memory usage and performance.
Document editing and wikis
In wikis and collaborative document platforms, 'revert' is central to edit history management. Reverting a document to a particular revision cancels subsequent edits, and the action is recorded separately in the history. This is the most basic means of responding to document vandalism, and during edit disputes, there are policies that restrict reverting itself, such as the 'three-revert rule (3RR).' Thanks to the undo/revert function, wikis can maintain completely open editing while still managing quality.
Version control systems
In distributed version control systems (DVCS) such as Git, undoing is done at the commit level. git revert creates a new commit that cancels the changes of a particular commit, while git reset moves the branch pointer itself to the past. The two differ in risk in that the former preserves history and the latter rewrites it. In other words, distinguishing 'undo that can be undone' from 'undo that rewrites history' determines the safety of collaboration.
Games and user experience
In games, saving/loading, checkpoints, and time-reversal mechanics are used as variations of undo. According to user experience (UX) research, the presence of an undo function makes users explore and experiment more actively, which increases learning and creativity. Conversely, irreversible actions require additional safeguards such as confirmation dialogs or two-factor authentication.
Reversal in law and administration
In law and administration, reversal is also institutionalized in the forms of cancellation, withdrawal, and restitution. However, for the stability of rights relationships, in certain cases it is restricted so that it cannot be undone (e.g., final judgments, exclusion periods); unlike technical undo, this is because the protection of third parties' reliance is prioritized.
Latest trends
Since 2023, as generative AI has been widely introduced into document, code, and image editing, the unit of undo is expanding from 'characters' or 'commits' to 'prompts and generated results.' While reverting AI-generated outputs to a previous state, prompt history management—tracking which prompt caused which change—has emerged as a new requirement. In 2024–2025, AI coding tools are trending toward automatically saving changes as checkpoints and including a feature to revert at once when problems occur.
At the same time, there are changes on the regulatory side. Regulations including the EU AI Act require human intervention and the possibility of canceling work for high-risk AI systems, and this is being organized into the design principle of 'reversible AI.' As reproducibility and auditability are emphasized, cases are increasing in which undo history itself is used as compliance evidence.
On the user interface side, beyond text-based shortcuts, voice commands, gestures, and multi-user undo in real-time collaborative environments (CRDT/OT-based synchronization that handles who undid what without conflict) are being researched. Ultimately, undo is evolving beyond a technical feature into a social and design promise to convert mistakes into learning rather than cost.
Related topics
- [[되돌리기]]
- [[버전 관리]]
- [[Git]]
- [[사용자 경험]]
- [[위키]]
- [[생성형 AI]]