Definition
A state in a version control system where multiple people edit the same line or adjacent lines in a file differently at the same time, causing the computer to pause and ask a human to decide because it cannot choose on its own.
Why Do Two People's Edits Clash?
Imagine dividing up tasks for a group project to write a single report. On page three, your teammate edits the conclusion to read "We support this plan." At the same time on your own computer, you change that exact same sentence to read "We oppose this plan." Now, you both try to combine your edits into one final document.
Computers execute commands quickly and reliably, but they cannot read human minds. The computer has no way of knowing whether "support" or "oppose" reflects what the team actually agreed upon.
If the computer picked one person's sentence at random and overwrote the other, someone's hard work would vanish into thin air. To prevent this, the computer stops in its tracks without discarding either version. This is a conflict caused by editing the exact same spot differently.
Looking Closer: How Git Compares Lines
Git, the most popular tool for tracking changes in code and documents, can automatically merge edits by comparing files line by line. If one person edits line 1 and another edits line 50, Git smoothly weaves both changes together without any trouble.
In reality, Git does not look at each line in isolation; it evaluates clusters of nearby changes as connected chunks. That means a conflict occurs not only when two people edit the exact same line, but also when they touch adjacent lines—like one person changing line 10 while another edits line 11. It also triggers when one person rewrites words on a line while someone else deletes that line entirely, or when one person modifies a file while another deletes the whole file (which Git reports via a status message rather than inline markers).
When lines collide, Git places markers (<<<<<<<, =======, >>>>>>>) right inside the file to show clearly who wrote what. Far from being a software glitch, this is a built-in safety net designed to protect your hard work from being lost.
How to Resolve and Prevent Conflicts
Seeing a conflict warning might feel intimidating, but there is no need to panic or rewrite your file from scratch. Open the file in any text editor, and you will see the changes neatly separated by Git's conflict markers.
Take your time to compare the two versions. You can pick the better option, or blend ideas from both to create a clean, unified sentence. Once you finish editing, erase the special symbols left by Git and save the file. Finally, tell Git that you resolved the problem (git add) and finish merging (git commit). With that, your conflict resolution is officially complete.
The best way to prevent conflicts in the first place is frequent communication and regular updates. Let your team know which files you plan to work on, and make it a habit to pull down your teammates' latest updates regularly before you start writing.
Common misconceptions
A merge conflict is a critical bug caused by writing bad code.
A conflict is not a defect; it is a normal, protective safety mechanism that keeps the computer from blindly overwriting your work.
Where you meet it
When one teammate changes a project deadline to 'Friday' while another changes the exact same line to 'next Monday.'
When a designer changes a button color to 'blue' and a developer changes that same line to 'purple', and they try to combine their code.
In one sentence
A safety feature that pauses the computer and asks a human to choose when the same or adjacent lines are edited differently.