The Issues Stats provides a snapshot of approval statuses of your products across all channels, as well as displaying the total number of account-level or catalog level issues for Google and Facebook only.
Please note that Bing does not provide Account-level issue/error reporting, only product level and API level:
Active: Approved, eligible products for advertising
Disapproved: Not eligible, have errors preventing advertising
Pending: Typically Google-only, your products are awaiting review by the channel
Errors: The total number of cumulative account or catalog errors for Google and Facebook