Well, Chris Saxon, an Oracle Developer Advocate for SQL, explains it all. 

Chris Saxon

Most applications store a wide variety of text such as names, addresses, and descriptions. When searching on these values, often you want letters in the values to match the search pattern disregarding the case.

In Chris’ latest post, you can gain more information on how to perform both Case-insensitive search and Accent-insensitive search, how to sort rows regardless of the case or accents and how to define search and sorting roles for a column. Chris also explains how to ignore case or diacritics before Oracle Database 12.2 and how to create indexes for fast searches.

Chris’ job is to help you get the best out of the Oracle Database and have fun with SQL. To help you with this he blogs at ALL THINGS SQL. He also creates videos combining SQL and magic on YouTube at THE MAGIC.