The Frase Topic Score, found in the "Optimize" tab, is the key component of Frase's Content Optimization workflow (screenshot below).
Frase recommends topics by analyzing the top Google results for your target search query and performing NLP analysis over them. In a nutshell, Frase extracts content from each URL and then leverages proprietary Named Entity Recognition to extract topics.
The orange vertical bar notes the average topic score across those Google results, while percentage number and green horizontal piece show the topic score of the content currently in your Frase editor.
Each time one of these topics is added to your editor, another mention will show in the score. So if "social media platform" in the screenshot above is 0/1, but then it gets mentioned once in the Frase editor, the score will read 1/1 and your Topic Score will increase. The right side number (the "1" in 0/1) is the average number of times the topic is mentioned across its sources, while the left side number is the number of times it's mentioned in the Frase editor.