Duplicate of Unique field?

If you want to validate unique field among the website then you can use Unique field module, but while you require to validate duplicate title for particular content type then you can use Unique Content Title module.

Unique field Usage:
For example, if you have a content type with a date field and there should only be one node per date, you could use this module to prevent a node from being saved with a date already used in another node.

Unique Content Title Usage:
For example, if you have a content type (Let's say Article) with a date field and there should only be one node per content type, you could use this module to prevent a node from being saved with a date already used in another node.

Thanks,

Still not clear what is the difference with "unique_field" module

Yes.. Still not cleared Title itself a field so what is the difference in unique content Title and Unique field