The Knowledge Graph is a technology created by Google that shows relevant information about a search query in the upper right corner of search results. Results from Knowledge Graph and other sources appear in Google Knowledge Panel. To change the panel, change the information from where it gets its data. This isn't always possible, but sometimes it is.
The Knowledge Graph is intended to be a databank that stores, organizes, connects billions of pieces of data so that users get the most relevant results for their intended searches.
Knowledge Panel pulls information from various sources, including the Knowledge Graph, to create a handy above-the-fold information space. It looks like this:
There is no direct way to apply search engine optimization techniques to Knowledge Graph, but the data sources it uses can be manipulated. A blog post that outlines Knowledge Graph SEO can be found here.
Google Knowledge Graph gathers data from a variety of sources, including:
Wikipedia, Wikidata, and Google Business, as well as other sources (none are all known outside of Google), can be changed by a user. Other data sources cannot.
To change Google Knowledge Panel, change the source data, or the search engine relevance of the target content. For example, if you want to change images that are in the Google Knowledge Panel, they have to be relevant. To make certain images relevant, use image SEO.