Tag Combos are a great way to filter what displays in your widget more precisely. In addition to showing 'all' the Pages containing the tags that you have selected, you can also adjust the conditions, so that what displays must match every tag, otherwise, it will not show.
LET'S EXPLAIN TAG COMBOS:
Can Match Any Tag: Shows any Pages or Files that contain any of the Tags that you have selected.
Must Match All Tags: Shows only that Page of File that matches all of the Tags that you have selected.
You can see in the previous Furniture Store example, that 'Chrome' and 'Office' are split into two separate tags. There is good reason for this. In same Furniture Store, you also have Chrome Bar Stools. Therefore, for the Chrome Bar Stools category, you would tag in the most granular way, like this.
FURNITURE | CHAIR | CHROME | HOSPITALITY | BAR STOOL
Now imagine that you would like to run a promotion on all Chrome Chairs. You add a new Page called Promotions, then drag in a Grid Layout onto the Page. You open the Widget and select Tags for 'Furniture and 'Chrome'. Your Grid Widget will now display Pages for all Chairs that are Tagged with 'Chrome'.
However, you now look at your page on the front-end and you quickly realise that your Page Widget is also displaying Chrome Tables. This is because your Tag Combos are still set to 'Can Match Any Tag'. This means that it can match all Chairs and Tables that have the tag for 'Chrome'.
You quickly change your Tag Combos to 'Must Match All Tags' and click Save. Within an instant, your Page Widget is now showing only Pages that are Tagged with 'Chairs' and 'Chrome'. This is because there is no Tag for 'Tables' in your selection. You are now happy that your Promotion is ready to go and displaying all Chrome Chairs in your store, and no Chrome Tables.