The phrase "common theme" refers to an idea or subject that appears repeatedly in different situations or works. It is a recurring topic that connects different things together. Full definition
It's anonymous so people can respond without worrying about judgement, and the survey does all of the work of searching for common themes in your personal brand. (greatresumesfast.com)
Communication (they missed their partner emotionally, weren't being understood emotionally, or weren't feeling loved) was the most common theme of the marital discussions. (gottman.com)
Issues of distance, identity and vulnerability emerge as common themes among the works on view. (artspacenc.org)