what is difference between Exception handling Application block & Exception handling in regular dot net classes ? i don't think it is beneficial to use of Exception handling Application block. What is exact use of that block ??
The Exception Handling Application Block offers helper methods that follow best practices as defined by Microsoft's Patterns and Practices group. You don't absolutely need it, but I've found the Blocks to be handy in many cases.
If you decide not to use it, you can still peek into the source for some great guidance on exception-handling best practices.