Cross object formula in Salesforce?

Hi Anjali,
Cross-object formulas:
Cross-object formulas are formulas that span two related objects and reference merge fields on those objects. Cross-object formulas can reference merge fields from a master (“parent”) object if an object is on the detail side of a master-detail relationship. Cross-object formulas also work with lookup relationships.You can reference fields from objects that are up to 10 relationships away. Cross-object formulas are available anywhere formulas are used except when creating default values
NOTE:- If you create a formula that references a field on another object and display that formula in your page layout, users can see the field on the object even if they don’t have access to that object record. For example, if you create a formula field on the Case object that references an account field, and display that formula field in the case page layout, users can see this field even if they don’t have access to the account record.
Cross-Object Field Updates:
For all custom objects and some standard objects, you can create workflow and approval actions where a change to a detail record updates a field on the related master record. Cross-object field updates work for custom-to-custom master-detail relationships, custom-to-standard master-detail relationships, and a few standard-to-standard master-detail relationships.
Please let us know if this will help you.
Thanks,
Visali.