Default Theme Content is a section containing the text and title of the sections/functions in the Theme. The reason these texts are not in Theme Settings is because it is related to multi-language. That's why we've arranged the text/titles of the apps/sections/features into the Default Theme Content panel. You can easily change them according to your purposes but still automatically translate them into multiple languages.
The easiest way to find a keyword you want to edit is to use the search engine. There are many tabs, and each tab has a lot of content, so if you find it manually, it will take time. Please copy the text you want to change and paste it into the search; it's easy!
Please watch the video below to learn how to edit the Default theme Content :