Merge Conflict

Definitions

Merge Conflict occurs in version control when two branches have made competing changes to the same lines of a file, or when one branch deletes a file that the other branch modified, making it impossible for the system to automatically reconcile the differences. When Git encounters a merge conflict, it marks the affected sections in the file with conflict markers (<<<<<<, =======, >>>>>>>) showing both versions, and requires a developer to manually resolve the conflict by choosing one version, combining them, or writing something entirely new. Merge conflicts are a normal part of collaborative development, especially on active projects where multiple developers work on related code simultaneously. Strategies for minimizing conflicts include keeping branches short-lived, merging from the main branch frequently, communicating about who is working on which files, and structuring code in small, independent modules. Tools like VS Code, IntelliJ, and dedicated merge tools provide visual interfaces for resolving conflicts more easily than editing conflict markers by hand.
In plain English: When two people change the same part of a file and the computer can't figure out which version to keep — someone has to manually sort it out.