What are watched records?
When you are watching a record, you will be notified whenever someone comments on the record. As a reminder, in order to receive notifications from Airtable, you will need to ensure your notifications are turned on and that you have verified your email address associated with your Airtable account.
How do I watch a record?
There are three general ways to watch records. One way is by manually choosing whether or not to watch a record in an expanded record. Another way is through @mentions and/or comments. Finally, you can watch records by using a collaborator field type and ensuring the option to "Notify collaborators when they’re added" is turned on before adding new collaborators to records.
Expanded record watch settings
To configure your watch settings, simply expand a record. The right side of the dialog is the record's activity feed. At the top right you can click the feed icon (which resembles an RSS feed or Wi-Fi icon.) Clicking this will allow you to change your watch settings between "Not watching" and "Watching comments."

If you don't want to watch the record, you can just set your status to "Not watching" again. At this time, it isn't possible to enable or disable watching multiple records at a time using this method.
Watching via @mentions or commenting
If you comment on a record, or if another collaborator @mentions you in a record's comments, then you will automatically be set to watch the record in question. If you are not watching a record, you can also be notified if someone @mentions you in a long text field. For more on commenting and @mentioning, see the article titled "Comment on Records and @Mention Collaborators."
Watching via a collaborator field
When a collaborator field type is set up to "Notify collaborators when they’re added", it will automatically cause future collaborators to also be added to watching any records that they are assigned to.

If you wish to not have collaborators automatically watch records that they are added to, then you will need to disable this toggle.
Additionally, this makes it possible to watch multiple records at one time, by copying and pasting a collaborator's information to multiple cells at the same time. You can also use the fill handle, but note that both options will overwrite rather than append any existing collaborators added previously.

Finally, it's worth pointing out, that users will still only be able to disable watching records one record at a time by clicking the expanded view of a record as mentioned in the "Expanded record watch settings" section above.