When I was just starting my career in programming, I thought I would be creating new applications. And I did - I created a few applications from scratch. Maybe two or three of them. But for the most part what I've been doing is working with code written by someone else a while ago - legacy code.

What is legacy code? You could define legacy code as ancient applications that were written in the past. For me, legacy code is code written by someone else no matter how long ago - 15 years or 15 minutes. What's common about all applications that were written by someone else? You don't know how they work. To be honest and taking into consideration how quickly people usually forget what they wrote, sometimes your own code written a while ago can be considered legacy code - you simply don't remember how it works!