The global search allows you to quickly search through common entities rather than navigating to the entity and then using the search bar or using an advanced find, although those options are still available to you. Like the quick search on entity records, the global search will only pull results for Active records. For inactive records you will need an advanced find or use an inactive view from the specific entity. The global search by default will pull information for Contacts and Accounts, but you can add additional entities. The steps below show you how to customize your global search options.
Select the General Tab and scroll down to "Set Up Quick Find" and click Select next to "Select Entities for Search"
Add or remove entities from the Selected Entities List and click Ok
Make modifications to your Quick Find View if desired
The global search will search fields identified in the quick find view for the selected entities. If you want to add or remove a search field you will need to update the Quick Find View in your settings for the entity.