Yellow journalism is the use of exaggerating, hyping up, and using false ideas in newspapers and articles in order to gain more hits or attraction. Yellow journalism sometimes can contain no actual research on the topic and usually is very biased towards one party or another.
Yellow journalism started in the 1890s, where popular newspaper owners like Joseph Pulitzer would publish papers that were very much extreme and exaggerated. This caused a lot of people to either believe these outlandish papers or to lose trust in newspapers completely.
While the term "yellow journalism" is known to be associated with the past, it truly does still exist today. While newspapers are much rarer now than they were years ago, yellow journalism online is prevalent. In articles, online or not, people will still use hyperbole and false ideas in order to gain more attraction to their writing. This can also be seen in the form of "clickbait" which has to do with yellow journalism as well.