When Nintendo usually releases a Nintendo Switch firmware update, it results in a change in the version number and, at the very least, a few changes that have been made. For these updates to complete, the console must restart itself.
But every now and then, the company will release a firmware update that doesn’t require a reboot. These “no reboot” updates are usually very minor in nature and patch notes are not usually published for them, but they are very significant. For example, Nintendo released one tonight. You can see the tweet breaking the news below, along with what the update changed.