These settings change the font of all elements not covered by the header and navigation font settings. There is a wide selection of web safe and semi-web safe settings listed in alphabetical order. Web safe fonts are standard system fonts (e.g Arial and Times New Roman) most people should have installed on their computer viewing your website. Semi-web safe fonts are fonts commonly installed with software such as Microsoft Office, iWork, Adobe Creative Suite and other productivity software. If the person viewing your site does not have the selected font installed, a close alternative font will be used instead.
Please note that some third-party plugins have their own font settings which will be used instead of fonts selected in the theme settings.