Cloud storage is an online service that stores your files on remote servers instead of on a local device. A remote server is a powerful computer in a data centre, owned by the cloud provider rather than by you.
Local storage, such as a hard drive or USB stick, keeps files on the device itself. With cloud storage, files are held on the provider's servers instead, so your own device does not need the space to keep them. Your device sends a request over an internet connection, and the server sends the file back.
For example, if you write a script for a school play on the computer in the drama hall, saving it locally keeps it on that computer only. Saving it to cloud storage uploads it to the provider's server, so you can open the same script later on your tablet at home, without copying it across on a USB stick.
Collaboration in cloud storage means several people can open and edit the same file at the same time. Their changes appear almost instantly for everyone, so you can work together without emailing versions back and forth.
Synchronisation is the automatic process that keeps files the same on the cloud and on every device linked to your account. When you save a change on one device, it is uploaded to the cloud and then downloaded to your other devices.
For example, four students in a robotics club keep a shared build log in the cloud. One types the list of parts, another adds the measurements, and a third writes about the motor that kept jamming. Everyone sees the new text as it is typed, so nobody is working on an old copy. This works because the file itself lives in the cloud rather than on one person's device.
Imagine you start drafting a speech for a debate competition on a library computer. You save it, and synchronisation copies it to the cloud. Later, you open the same file on a laptop at home and add a new paragraph. That change is uploaded to the cloud and then copied back to the library computer the next time it is online. You always work on the most recent version, whichever device you pick up.
Synchronisation also means copies of your files sit on several devices, not just one. If one device breaks, your work is still in the cloud and on your other devices.
Full synchronisation and selective synchronisation are two ways to set up which files are copied between a cloud storage account and your linked devices.
In full synchronisation, every linked device stores a local copy of the synchronised file. That means each device holds the complete set of files, so you can open any of them even without an internet connection. The downside is that every device needs enough storage for everything, and copying all the files can use more data and take longer.
Selective synchronisation is a setting in the sync app: instead of copying every file down to a device, you tick the folders and files you want it to hold. For example, a school music department might sync its whole shared folder to the office desktop, but only the current concert pieces to a classroom tablet with limited storage. This saves space and reduces sync time on that device. Anything you leave out stays safe in your cloud account and you can still open it when you have an internet connection, but it will not be available offline there.
| Aspect | Full synchronisation | Selective synchronisation |
|---|---|---|
| What is copied | Every synchronised file | Only the files or folders you choose |
| Local copy on each device | All devices store the full set | Only the chosen items are stored locally |
| Storage and data use | Higher on every device | Lower on devices with fewer selected items |
| Good for | Devices that need the complete set | Devices with limited storage or a specific purpose |
A portable handheld device, such as a smartphone or a small tablet, lets staff reach cloud services from wherever they are on site. Details can be checked on the spot, so nobody has to break off from the job to fetch them.
For example, at an outdoor activity centre, an instructor can check the next session's booking and safety notes on a handheld device while standing by the climbing wall. The device fetches the booking from the central cloud system, and real-time synchronisation keeps it up to date. If the office changes the booking, the instructor sees the new details straight away rather than working from an old printout.
Cloud storage keeps your files on remote servers, so you need an internet connection to reach them. Without one, you cannot upload, download or open the files held in the cloud.
Because your files are stored online rather than on one machine, any internet-connected device can reach them — a library computer, a tablet at home, or a phone in a café. The service itself runs 24/7, so you can work whenever it suits you, as long as you have a connection.
It must be an internet connection, not just your home Wi-Fi: mobile data works too.
The speed and reliability of your connection affect how quickly files move. A fast, stable link transfers files in seconds, while a slow or patchy one makes large files frustrating to work with.
For example, a 500 MB folder of project files takes about 40 seconds to download on a 100 Mbps connection, but roughly 6 minutes 40 seconds on a 10 Mbps one. If the connection drops part-way through, the transfer may fail and you would have to start it again.
Some cloud services let you keep working when you have no internet connection. This is called offline access. Your device keeps a local copy of the files you have chosen to make available offline, so you can open and edit them even when you are out of signal.
When you edit a file offline, the changes are saved on your device first, and your device records that the file has changed since it was last synced. The next time your device has an internet connection, it synchronises with the cloud. Your edits are uploaded to the cloud copy, and any changes made elsewhere are downloaded, so every device ends up with the same version.
For example, Dhruv is on a school bus with no signal and adds notes to a project file he made available offline. The edits stay on his tablet. When he gets home and connects to the internet, the file synchronises, and his teammates see the new notes on their devices.
Offline access does not mean cloud storage works without the internet. You still need an internet connection at some point to synchronise your changes with the cloud and other devices, and you normally need to have made the file available offline while you had a connection. Until then, the cloud copy stays out of date and other people cannot see your work.
A notification is an alert that tells you something has happened. It can appear when a new message arrives, or when someone changes a shared document or plan, such as a rota, project plan or appointments list.
Notifications do more than just say “something changed”. They can show who made the change and when it was made. For example, a practice manager at a veterinary surgery updates the shared staff rota to cover a sick colleague. A notification tells the other staff that the rota changed, names the manager, and gives the time. Staff can then check the new shift and arrange cover quickly instead of finding out later.
Staff do not need to keep reopening every shared file to look for changes. A notification brings the update to their attention, so they can respond quickly. This is useful when a plan changes at short notice, such as a delivery time moving or a meeting room being swapped.
Notifications can also alert staff to new messages in a shared workspace, not only edits to documents. This helps a team notice questions, approvals or instructions without waiting for someone to pass the message on in person.
A mixed system uses everyday local hardware — a laptop, tablet or desktop computer — alongside a cloud service. The device does the processing and keeps files it can open straight away, while the cloud provides storage you can reach from any location with an internet connection. The two halves are joined together by synchronisation, so the local and cloud parts behave like one system rather than two separate ones.
Picture the cloud as the hub of a wheel and each device as a spoke. Every device holds its own copy of the files in a synced folder, and a small sync program compares that copy with the hub.
Because every device checks against the same hub, changes travel in both directions and the copies stay consistent between devices and locations. A device can also keep working on its own local copy when there is no internet connection, then synchronise once it reconnects.
| Job | Where it happens |
|---|---|
| Opening, editing and saving a file | On the local device |
| Holding the master copy every device checks against | Cloud storage (the hub) |
| Spotting which copies differ and moving changes each way | Synchronisation |
A notification is an alert the cloud service sends when something in a shared folder changes. It tells you who made the change and when, so a group working on the same plan knows straight away that it has been updated and does not carry on using an older version.
A school drama club builds its running order on a tablet in the hall, while a teacher adds prop notes on a classroom laptop. Neither machine is in the same room, yet both save into the same synced folder. The tablet uploads its updated running order to the hub, the hub sends it down to the laptop, and the laptop's prop notes travel back up and down to the tablet. Next morning both devices show one identical, up-to-date plan — no memory sticks and no emailing files to yourself.
A program can check a device's folder against the hub and report which way each file needs to travel:
local_files = ["running_order.txt", "prop_notes.txt"]
cloud_files = ["running_order.txt", "prop_notes.txt"]
# anything only on the device must go up to the hub
for name in local_files:
if name not in cloud_files:
print("Upload:", name)
# anything only on the hub must come down to the device
for name in cloud_files:
if name not in local_files:
print("Download:", name)