AND requires each condition in a group to match. OR accepts a record when it matches either group. For an active network queue, Active is true AND Category is Network excludes inactive network incidents and active incidents in other categories. Replacing AND with OR includes both unwanted sets.
Read grouped conditions as a sentence before running them. The simulator places AND within a group and OR between groups. To find active hardware or software work, repeat Active is true in both OR groups. Breadcrumbs let you see and remove part of a filter; removing an early condition can broaden the queue. Use new matching and nonmatching records mentally to test the definition, especially when the visible result is empty or contains only one row.