What is Google Phantom Update about?

It appears that Google didn't admit there is such.
But to be safe, is always good to maintain quality site.

Here are several important things to keep in mind:

Duplicate content and redundant articles are a no-no.
Avoid creating thin content.
Prioritize user experience. For example, too many ads on your site can create a negative visitor experience and have an undesired impact on your rankings.
Your content should be trustworthy. Visitors that land on your site should feel comfortable giving you their credit card information.
Are you exercising quality control with your content? Your articles should be free of spelling and factual errors.
Are you striving to give your target users an in-depth look into the subject matter? Does your content meet their needs?
This is just a quick overview of what Google expects from you as a content creator. From a user experience perspective, it makes a lot of sense.
SOURCE

Quote from: PaulaEdwards on 2017-03-24 08:23
What is Google Phantom Update about?

Google's Phantom update was a sneaky change to the company's search algorithm that affected mostly informational sites like eHow, Quora, and HubPages. Many sites lost rankings while others jumped ahead, causing mass confusion among webmasters as Google originally denied a major update.

Google's Phantom update is also known as Quality Update. After many reports of large-scale ranking changes, originally dubbed Phantom 2, Google on  2015, acknowledged a core algorithm change impacting "quality signals". Google Phantom 2 algorithm assesses content quality on a website. This update seems to have had a broad impact, but Google didn't reveal any specifics about the nature of the signals involved.