It has always been Google’s goal to provide the best results when using their search engine. The Google algorithm has been finely tuned to look for the most up-to-date, high quality, and relevant sources on the web to fit the needs of enthusiastic searchers.
However, Google’s efforts to provide high-quality results were often thwarted by sites that used 'canned content', or content that has been published before. Content farms can produce search-engine-optimized websites at a fraction of the cost due to the reuse of general content. With cost-efficiency and built-in rankings, the popularity of these sites, at the time, was extremely popular. But, all that has changed with the power of content marketing.
In an announcement made in October of 2014, Google is taking an offensive stand against these low-quality sites. Simply by making a minor algorithm change, Google affected about 11.8% of queries. Sites are now more harshly judged on the originality of content and the depth of analysis provided. That being said, some sites will rise (ones with unique content) and others will plummet (most likely those with 'canned content').
Now, in my opinion, there are only so many ways you can uniquely explain how to make a peanut butter and jelly sandwich. With millions of sites on the web, there is bound to be some overlap in explanations and phrasing. Within a single industry, there are certain terms and phrases that will exist on all sites. And although we may never know the specific details, I would assume Google has taken this into consideration.
When the announcement was made, many people panicked and tried to switch up their content using a thesaurus or article spinning software. However, the one way to truly define your website as original, is through personality. Take this opportunity to inject some character into your site.