As you may or may have not noticed, Google did a big update Mid March 2018. Alot of sites were affected. Most were sites that were not following Googles Terms of Services. In other words, people trying to game the system by not building quality websites.
They really tried to clean up the search engines results so that could be more focused to Tamarac, FL. In an effort to do this alot of good peoples websites were knocked off or out of the results all together. To help explain what happened check out this articel by Search Engine Round Table:
Google Confirmed Weekend Algorithm Ranking Shift As "Core Update"
Mar 13, 2018 • 7:43 am
Yesterday we reported that we thought there was a Google algorithm ranking update over the weekend and to my surprise, Google actually confirmed it. Danny Sullivan at Google said on Twitter that yes, there was an update. He went to the @searchliaison account to explain in detail.
Google Confirmed This Update:
He said they "released a broad core algorithm update" last week and said they do these "several times per year." Google added that "each day, Google usually releases one or more changes designed to improve our results. Some are focused around specific improvements. Some are broad changes." This one was a "core algorithm update," which doesn't happen every day at Google. Older algorithms like Panda are now part of the core algorithm but there are many part of that core algorithm.
Yes, see here: https://t.co/gckGCFT9tJ— Danny Sullivan (@dannysullivan) March 12, 2018
Each day, Google usually releases one or more changes designed to improve our results. Some are focused around specific improvements. Some are broad changes. Last week, we released a broad core algorithm update. We do these routinely several times per year....— Google SearchLiaison (@searchliaison) March 12, 2018
What Do You Do If Your Rankings Dropped?
The answer, according to Google, is really nothing. Google went on to explain that "as with any update, some sites may note drops or gains." Google says your site may be fine, "there's nothing wrong with pages that may now perform less well," they said. "Instead, it's that changes to our systems are benefiting pages that were previously under-rewarded," Google added.
"There's no "fix" for pages that may perform less well other than to remain focused on building great content," Google said. So wait it out and improve your overall site and "over time, it may be that your content may rise relative to other pages," Google says.
There’s no “fix” for pages that may perform less well other than to remain focused on building great content. Over time, it may be that your content may rise relative to other pages.— Google SearchLiaison (@searchliaison) March 12, 2018
Not A Specific Update
Danny said on Twitter it was not a Maccabees Update or anything like that, since it was a core update. It was likely not Fred either. Well, that is assuming that I didn't name the Maccabees Update or Fred Update after a core update. :)
But you get the point. The core updates have multiple things baked into it, such as Panda and many other things. So overall quality updates can be a lot of things, many Freds, many Pandas, many Maccabees - but no, Google won't go down the path of naming it:
Because it's a core algorithm update, yes, there's no official name for it.— Danny Sullivan (@dannysullivan) March 12, 2018
Anyway, so there you have it, this was a confirmed update, that only happens several times a year. If you were hit by it, then there is no specific advice outside of make your site better.
Forum discussion at Twitter.
Barry Schwartz first reported on this at https://www.seroundtable.com/google-confirms-core-update-25390.html. You can read more of this story there.
I will tell you from my customers experiences all of our websites went up in rankings or stayed at the top. So for what it is worth you need to design good site structure for your websites too last all future updates.