As an alternative to deleting a record, you can make it inactive. Inactive records do not automatically appear in searches, queries, or reports and cannot be associated with other records. However, unlike deleted records, they remain in your database for historic purposes. For example, you cannot associate gifts with an inactive fund, but the information for that fund record is still available in your database.
If you want inactive records to appear in your queries, you can mark a user option to do so. If you want inactive records to appear as search results, you can mark a checkbox on the Open screen each time you search for a record of that type. Different reports vary, but for many of them you can mark a checkbox if you want to include certain types of inactive records. You can reactivate a record you have marked as inactive.