IWSG: What is Passive Voice?

It's the first Wednesday of the month, and time for members of the Insecure Writer's Support Group to share their writerly insecurities. The group was started by Alex J. Cavanaugh, and those interested in joining in can visit www.insecurewriterssupportgroup.com for more information.

We've entered the last month of the year, a time when most writers can be found tallying their NaNoWriMo word counts. But as I am sure you already know, I'd elected not to take part in last month's NaNo. Still, I usually do some tallying of my own every December, in the form of a week-long, year-in-review-themed series of posts; be sure to join me on the week of Christmas, as I recount my favorite songs, albums, movies and more.

Right. Now that the shameless plug is out of the way, we can touch upon a topic I am sure most writers are familiar with by now, namely the use of active voice vs. passive voice. I was talking with a non-writer acquaintance the other day, when the topic came up, so in a way, this post is written for her benefit, assuming she happens to stumble across my blog somehow.

While I haven't been writing any fiction books lately, the nature of my day job finds me doing other forms of writing, such as advertisement copy. And even in the realm of content writing, writers are advised to avoid using passive voice. Which begs the question, what exactly is passive voice?

Rather than lunch into a lengthy one-sided explanation, I'd like to leave the question open to any IWSG members who might be willing to contribute to a discussion on the subject matter. After all, I am far from an authority on the subject, having once been accused of using too much passive voice in some of my earlier works. So I ask again, what is passive voice, and why is it considered less engaging than active voice?