What does “in-house application” mean? How to translate it?

I have problem with translating this sentence:

"Running in-house systems means that you can leverage your existing security system for purposes of authentication, authorization, and so forth" - from Pro C# 2010 and the .NET 4 Platform

Google translate doesn't help me with this.

I don't want to translate it to my language, but I want explanation, the best with some examples.


Software written and used within the same company.