Why is error handling important?

Question

I was given a task of write the coding guidelines for my team, and it was going great until my manager asked me to write an explanation of Why Error Handling is Importan

Answer 1

First I would ask is it important?

I've seen (ugly) code where some errors were ignored (eg null reference)

So what type of errors are important to handle?

There is a big difference between System.IO.FileNotFoundException, System.Data.SqlClient.SqlException and System.ApplicationException