This page explains what synchronize means in the four ways people actually use it, from wristwatches to phone folders. It also covers the spelling split that trips up writers and the syncing-versus-backup confusion that quietly costs people files. Along the way you’ll see why two things you’ve matched up start drifting apart the moment you stop checking.
The core idea is simple, since the word describes making things match in time or in content. What most definitions skip is that a match never lasts on its own. By the end you’ll use the word precisely and know when a sync has stopped doing its job.
The Short Answer
Synchronizing two or more things means making them happen at the same time or at the same rate. It can also mean making them match in content. People use it for setting clocks, lining up sound and picture, timing movements, and keeping files identical across devices.
Four Meanings, With an Example of Each
Dictionaries split the word into several senses, but four of them cover most of what you’ll run into. Engineers treat the idea as a field of its own, and the encyclopedia article on coordinating events so a system operates in unison opens with an orchestra conductor keeping players in time. That image works well as a mental anchor for everything below.
- Happening together. Movements or events that occur at the same moment, such as a drumline hitting every beat on the same count.
- Setting clocks to match. Adjusting watches or clocks so they show the same time, the classic ritual before a big plan kicks off.
- Matching data. Making files, contacts, or settings on one device equal to those on another and trying to keep them that way, which is why a calendar entry made on your laptop shows up on your phone.
- Aligning sound and picture. Timing audio against video so a voice lands on the moving lips, or timing stage lights to a piece of music.
The first, second and fourth senses are about timing, while the third is about content. A synced folder doesn’t have to change at the same instant as its twin, it only has to end up holding the same files. Keep that split in mind, because the two kinds of synchronizing fail in different ways, and each failure has its own section below.
Why Two Matched Watches Never Stay Matched
Set two watches to the same second and they’re synchronized for exactly as long as their crystals keep agreeing, which isn’t long. Cheap watch crystals are often rated around 20 parts per million, and that’s a fair stand-in for plenty of consumer clocks. Turning the rating into daily seconds is just percentage math, since 20 parts per million is 0.002 percent, and 0.002 percent of the 86,400 seconds in a day is about 1.7 seconds.
The Two-Watch Arithmetic
A watch that gains or loses 1.7 seconds a day is no trouble until you compare it with another one. If one runs 20 parts per million fast and the other runs 20 slow, the gap between them grows at 40 parts per million, which is about 3.5 seconds a day. After a 30-day month, the two watches you carefully matched at four o’clock would disagree by about a minute and 44 seconds.
That’s worst-case arithmetic, not a measurement, and many decent watches do far better. Temperature nudges a crystal’s rate too, so even a good watch behaves a little differently in a cold pocket than on a warm wrist. Whatever the exact numbers, the gap only grows until somebody resets it, so any plan that depends on matched clocks needs a re-check built in.
How Computers Keep Correcting Themselves
Computers face the same problem and solve it by resynchronizing constantly. Many devices use the Network Time Protocol, which repeatedly asks a more accurate clock for the time and adjusts the local one to match. Over the public internet that typically holds time to within tens of milliseconds, and on a local network under ideal conditions it can beat one millisecond.
At the top of the chain sit reference clocks such as GPS receivers and atomic clocks, and each level below copies the level above it. Accuracy slips a little at every level and with every extra stretch of network between you and the server, which is why a nearby server beats a distant one. The trick isn’t owning a perfect clock but checking again on a schedule.
A Practical Way to Synchronize Two Watches
Most people match watches by eyeballing them, which quietly passes one watch’s error to the other. A better method sets every watch against a single shared reference, such as a phone clock that gets its time from the network. The steps below assume analog watches with a crown.
- Choose one reference clock and use it for every watch in the group.
- Pull the crown out to the time-setting position, which on many watches stops the seconds hand, and set the minute hand one minute ahead of the reference.
- Push the crown back in at the instant the reference clock reaches the top of that minute.
- Repeat for each remaining watch, then re-check all of them against the reference after a week and again each month.
The Sync Mistake That Costs People Files
A lot of people treat a synced folder as a backup, reasoning that a file living on a laptop and a phone as well as in the cloud must be safe. That feels right because the file really does exist in three places. The catch is that sync software has one job, which is making every copy identical, and it applies that job to mistakes just as faithfully as to good edits.
Delete a file on one device and the deletion usually travels to the others. Save over a document by accident, or let ransom ware scramble a folder, and the damaged version can replace the good one everywhere within moments. Many services keep deleted files or earlier versions for a limited time, which can rescue you, but that’s a recovery feature added on top of syncing, not part of it.
Conflicts are the other quiet failure. If two devices edit the same file while one of them is offline, the service has to pick a winner or keep both versions, and the winner isn’t always the one you’d have chosen. Some services save a second copy with a conflict label instead of overwriting, which is safer but leaves you to merge the two by hand.
The correct mental model is that syncing protects you from a lost device, while a backup protects you from a lost decision. If a laptop is stolen, your files are still in the cloud and on your phone. If you delete the wrong folder on Tuesday, only a backup with history, kept somewhere that doesn’t mirror your changes, gets it back on Friday.
Mirroring is not the same as remembering.
Synchronize or Synchronise, and Where the Z Comes From
Both spellings are correct, and the difference is regional rather than a change in meaning. Synchronize with a z is standard in American English, while synchronise with an s is the usual British choice. British writers who follow Oxford style use the z as well, so seeing it in a UK publication doesn’t mean an American editor got there first.
Several spelling guides credit Noah Webster with the z, but the letter is older than he is. The word comes from a Greek verb meaning to be contemporary with, and dictionaries date its first appearance in English to the early 1600s. That makes the z the form closest to the Greek source. Whichever you choose, keep it consistent, since sync, synced and syncing are spelled identically in both varieties.
How Synchronizing Differs From Coordinating and Aligning
Coordinate and align both sit near synchronizing in a thesaurus, but neither carries its sense of timing. To coordinate is to make things work together without saying when, and to align is to point them the same way. Synchronizing is the one that cares about time or rate, which is why you can align the columns of a spreadsheet but can only sync a set of clocks.
Conclusion
To synchronize is to make things match, and the useful half of that idea is that a match has to be maintained. Re-check your watch against a trusted reference once a month, and spend five minutes today confirming that anything you keep in a synced folder also exists in a backup with version history. Do both and the word stops being vague. It becomes a small routine you actually run, which is the only way synchronized things stay that way.
FAQ
Is it sync, synch or synchronize?
Sync is the everyday short form of synchronizing, and it dominates in tech writing. Synch is a variant that’s still understood but appears less often. Sync keeps the same spelling in American and British English, so it’s the safe abbreviation.
What is the opposite of synchronize?
In everyday speech the natural opposite is out of sync. Technical writing calls uncoordinated systems asynchronous, and desynchronize describes breaking a match on purpose or by accident. No single antonym fits every context, so the right word depends on whether the subject is time or data.
Do you synchronize with or to something?
The standard pattern is to synchronize one thing with another, as in a calendar with a phone. Files can also be synchronized between two computers. A fixed reference such as a beat or a clock often takes the word to instead.
Can I stop a synced folder from deleting files everywhere?
Often, though it depends on the service. Common options include syncing only selected folders, upload-only modes, and checking for a recycle bin or version history. Read that service’s own settings first, because defaults differ between apps.
Does synchronized always mean at the exact same instant?
No, it means coordinated in time, and the coordination can be deliberately offset. Cambridge Dictionary’s example is traffic lights timed so cars at a steady speed keep meeting green, which only works if the lights change at staggered moments.