How do I restore data changes made after the backup?

Newbie here...

How do I restore data changes made after the backup? I've been combing the
docs and the web site but I don't see anything on this. Given a backup taken
this morning, and a failure requiring a database restore, how do I restroe
the data that was added after the backup was taken this morning? Isn't there
any log files to apply to pg_restore? Does PostgreSQL have the ability to
restore to the point of failure so no transactions are lost? (Like Oracle?)
Is replication commonly used for this? 


Please advise,
Steve Orr