Pros and Cons of SQL Server back up strategies and their appropriate usage scenarios
Log shipping is not a backup scenario. It's a semi high availabiliy scenario.
For backups there's full, differential and transaction log backups.
They should all be used together. Your SLA dictates how you use them.
Most typical scenarios are full backup say at midnight, diff backup at noon and transaction log backups every 30 or 15 minutes.

And remember: you don't have a valid backup until you restore from it to test if it's ok.