Tertiary resources are written for the General Public and are much easier to understand than the primary and secondary articles they are based on.
Tertiary resources are written by journalists and are meant to summarize research in an easy to understand way. Think about listening to the news and hearing about new studies about drugs or treatments, those are great examples of tertiary news.
Tertiary resources are NOT peer-reviewed, but are instead based on trusted information. Keep this in mind while looking for tertiary resources.