So what are seamless updates? As the name implies, seamless updates are when your handset receives an update and installs it in the background without you, the user, having to do anything. When you reboot your phone, the new update will be installed, which means that you won’t have to wait for update prompts and so on.
It sounds simple enough but unfortunately due to the technical requirements needed to pull it off, existing devices won’t be able to use it. This is because seamless updates requires the handset to have two partitions, kind of like partitioning a hard drive, where one is where is in use by the phone at all times, and the other remains free to be updated by the system.
However like we said, it would be unreasonable for Google to expect all Android users to be technically proficient to partition their phones themselves. Even if there were instructions, we reckon that there will be a flood of forum posts in which things go wrong as a result of it, so for now it looks like only future handsets that have already been partitioned will get the feature.