At the end of each workday, *John* updates the curriculum files for a chain of English-language schools in Taiwan. Errors are fixed, changes are made and the next day, teachers spread across branches all over the island fire up their Mac minis, and a file sharing app syncs up the latest version of their school's teaching materials. John uses a cloud service - naturally - and in his case it's Dropbox. Why? Because Dropbox supports delta sync - meaning when files are updated, instead of re-uploading the whole file, only the part which has been changed is uploaded. It's the most efficient system for his needs.

Of course, Dropbox has plenty of competition, from Google Drive - which offers more free space than many other services - to Microsoft's One Drive, which offers services in 107 languages and works well with the company's suite of office software. Others such as SugarSync are moving up the rankings quickly, and it's likely almost every service will soon be adding extras such as edge computing, AI, analytics, and more.

So, in 2021, which cloud service is the "best"? The answer doesn't lend itself to superlatives. There is no "best." It's the cloud server that works best for your needs, which includes your budget. Some don't have a lot of choice. In China, it's pretty much Alibaba cloud or some much smaller domestic alternative. Luckily, the rest of us are spoiled for choice.

We might not be able to say who's "the best," but we can make some comparisons that could help you determine which cloud to hop on. Sometimes it's easy. Many Windows users will find One Drive the simplest and strongest choice. After all, it's the default online storage service for both Windows 10 and Office 365, used by hundreds of millions of people. One Drive is a powerful tool and has apps for more platforms than its competitors.

But Google Drive gives more for less. In fact, most users won't need to store more than 15GB worth of data. Should that limit be a problem, however, Google Drive's pricing is more than reasonable. If you're in the Google ecosphere, it's going to be hard to get you to abandon Drive as it's an excellent service.

Apple fans are likely starting to scream about the marvels of iCloud. It must be admitted, however, that iCloud Drive isn't quite as awesome as Dropbox, One Drive or Google Drive - one example being the inability to use online versions to edit documents that include tracking. But to be fair, Apple often ends up improving on almost everything so it could one day be the hands-down winner - if, of course, you're using devices running iOS.

Dropbox is probably the winner in the 'ease-of-use' category. It was one of the first in the business and it's stayed reliable and simple, doing the basics very well. As mentioned above, many appreciate the delta sync support and as an aside, many Dropbox fans note that they'd rather keep their data away from the mega players - who already have more than enough of everyone's data. Finally, Dropbox also wins in the "third-party integration" category - something it does better than most.

Some interesting newer kids on the block include IDrive, where you can get 5T for just under US$100 a year and Box, a service some in the corporate world prefer. Box gives users 10GB free, which is great... except for the restriction of 250MB per file upload for non-paying users. You won't be using Box (for free, that is) to upload a video project, for example.

Privacy is a big deal for some and there are plenty of options for those with stuff to hide (just kidding, privacy is a genuine concern that more of us should take seriously). CertainSafe Digital Safety Deposit Box has some attractive features: bulk data breaches of cloud-stored files are impossible, past file versions are retained, and file sharing and chats are secure. Don't, however, forget your password or your security question. This powerful encrypted service doesn't compromise for the forgetful - don't remember your password? - You're out. A strong alternative to CertainSafe is AxCrypt Premium, offering some seriously advanced encryption features that don't require a degree in rocket surgery to understand.

CryptoForge, Cypherix SecureIT, NordLocker, CryptoExpert, and Steganos Safe, and SpiderOak One are all worth taking a look at if your primary need is preserving corporate secrets. Many of the privacy-centered optioned mentioned above come with a zero-knowledge, or no-logs policy. The firm gives you the software, but every byte of data stays on the user's side, meaning no one but the user can ever access an encrypted file. Some like to use services that come with zero-knowledge policies for backups, which can be a smart idea.

To recap, with so many options for cloud services in 2021, you likely need to make a list of what's the priority for you or your organization. After looking over your specific needs, look over the specs of each service and pick. It might be a lot to think about, but it sure is nice to have options.