How Does Arcamatic Know Which Files Have Changed?

Arcamatic Client goes through it's local files and generate hashes of all target files and then sends that list of hashes to the Arcamatic Server to compare with a similar list of it's own. It then generates a list of files that have changed and share that with the Arcamatic Client so they both know which files need to be transferred in order to synchronize the target directories.

This way, Arcamatic only send files that are missing or different. Arcamatic also compresses each file before sending it in order to reduce network bandwidth used.