Sync 2.5 introduces two editions - Home and Business - for personal home and commercial office usage accordingly. The major difference between these two is the set of features available and licensing (see below). This means that both these editions still offer the same privacy (your files are stored only on your devices and are not exposed to a third party), security (all files are transferred though encrypted channel) and performance.
The current edition being used can be seen on Sync app header.
Sync Home can be used as a Free app, as well as Pro licensed app which gives some pro features. Sync Home Pro license is a non-subscription one-time payment license. Before making the license purchase you can enable 14-days' Pro Trial period in Sync preferences -> License.
Sync Family Pro is basically the same Sync Home Pro license key, which lets you save on bulk purchase. This license plan fits the case when Sync is being used by up to 5 family members each of whom can just use the purchased license key.
Sync Business requires subscription type of license. It has 14-days Trial period enabled by default upon installation. Once Trial expires, license is to be applied (what happens when trial expires?). Sync Business has Sync Business Accelerator edition which has WAN speed optimization feature and can be used on servers (see below).
Here's the chart comparing the features:
Most features have been here for quite a time, those on blue cells are introduced in Sync 2.5.
Advanced - coming with new, advanced functionality, and Standard - offering simplified functionality, Encrypted - keep the files encrypted on an untrusted storage. Advanced folders make use of X.509 digital certificate, which ensures that such operations as adding peers, sharing folders, revoking access to folders, etc are done in a secure way. SSL is used to provide security for peer data exchange over network. See this article for more detail about Advanced vs Standard, and here for more details about Encrypted folders.
All Sync editions can run on mobile devices. Mobile devices don't differentiate between these Sync editions.
Sync now shows extended events in history, allowing to filter them by warnings, errors, info and general activity.
This option allows to selectively download only those files that you currently need and clear them off from device when they're no longer needed, it helps to save storage on a device. Learn more...
You can link all your devices with one identity. It eases folder sharing - folders appear on all linked devices automatically without having to do it manually. Learn more...
This is a weekly schedule that gives some flexibility in limiting the bandwidth on certain days and hours. Learn more...
Available only in Advanced folders. This option allows to remotely change other peers' access to the share, as well as disconnect them from it. Lean more...
This is a file sharing option. Files can be shared either via a link or QR code. Sync Home Pro can set link expiration date up to 7 days, Sync Business can set link to never expire.
Diff delta sync:
Sync is smart enough to detect that a piece of file has changed and re-sync only this one instead of the whole file. But diff delta sync option takes it further - if file update caused all other pieces to shift (e.g. new data was added to the beginning of the file), Sync will still retransfer only the changed piece and insert it in the correct place.
This is transfer optimization feature that also reduces excessive traffic. When downloading a file, Sync first rechecks the folder tree of other shares. If the same file is found there, it's not synced from remote peers, but instead copied from the local directory.
Sync can communicate over new smart uTP2 protocol designed for bulk data transfer in WAN. This option allows speed up to 1Gbit/sec.
Running on a Server:
Server Operating System means all Windows Server group and Linux with non-arm based CPU. While both Sync Home editions and Sync Business Accelerator can run on these without restrictions, Sync Business requires license for that. Without this license, Sync Business can be utilized only on workstations.