Years ago, Google used to wait a few months at a time before unleashing new search engine code into the world (wide web).
As it stands right now, they have teams of different programmers working on different segments of the search engine at all times. Some teams work on web spam filtering, some on measuring links, some on basic page formatting. Each team works almost independently of any other team.
As these teams release new features, they are automatically added to a daily routine of mini updates for website ranking. Most of the time you won't notice a big change in how your web page is ranking with the new features; in fact, you are more likely to hear about some change on a blog post than noticing it yourself.
However, there will be day when you sit down with your morning coffee and discover that your website is suddenly a big Zero in search ranking. Yes, it happens. You can be on page 1 for "wedding rings jewelry store" on Tuesday and then not in the top 40 pages on Wednesday.
Don't panic if this happens!
There are two reasons for this to happen:
1. Epic failure of new Google code.
2. You are a dirty spammer and this is the day you got caught.
Usually the answer is #1 -- Google messed up. So wait a day or two and things should go back to normal.
On the other hand, if things don't go back to normal, then your SEO techniques need to be reevaluated. Did you hire an SEO company that "promised" or "guaranteed" results? If so, then you probably have some SEO no-no's on your website and are being punished.
If you didn't previously hire an SEO firm, now is the time to finally do it. Only an SEO professional will be able to figure out why you dropped so far in the rankings.
By the way, #2 above has an official name. When you are caught doing something wrong on your website it's referred to as a "Google Slap."
