To enforce data format using validation rule, which function should be used?

Which is the order of execution among these? Escalation rule assignment rule trigger
workflow rule validation rule auto-response rule?

To check if a field’s value has changed or not using validation rule, which function should be
used?

A user faces problem while logging into Salesforce. What should administrator do?

Universal Containers has two teams – sales team and marketing team. For sales team all
stages of lead lifecycle should be available while for marketing team only 3 stages should be
available. How can the administrator ensure this?

What license is needed to install or uninstall apps from AppExchange?

Force.com is good for

Which are the 3 tiers of an app?

Many-to-many relationship is created using?

The object used in many-to-many relationship is called as?