Knowledge Graph is technology Google uses to improve search results related to your website. GD SEO Toolbox Pro supports several elements for the Knowledge Graph, and you can configure them through 2 settings panels.
Website Graph allows you to set your website name, alternative site name, and URL for website internal search. This search will then appear in the search results top hit for your website.
Profile Graph allows you to specify Organization on Person website type, set logo and links to various social networks. This will appear as website profile block in the search results on the first page.
Mind you, all knowledge graph results are displayed only if Google decides so, there is no way to force them displayed, the plugin can add the graph data, but it has not control over the way Google uses the data.