Remember that scene from Office Space where the Bobs ask, "What would you say you do here?" I've been a production DBA for most of my 10+ year career and I've boiled down the non-technical answer to "I keep the lights on and the wheels turning". While it may be an adequate answer for a casual conversation, it's far from a fair description of what I do on a daily basis.
Recently I came across a blog post by Tim & Lori Edwards (Twitter: @timbo_b_edwards and @loriedwards) that I thought does a great job of answering that question and is worth sharing: What Is A Production DBA, Anyway?
Tim & Lori's blog – SQLServerTimes2 – is relatively new but they've got some good posts up so far. Go check out their post on being a production DBA, and while you're there take a minute to read their other posts and consider adding them to your RSS feeds.